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Ch. 4-5 HW & Test – Flashcards 45 terms
Karlie Mack

45 terms
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Ch. 4-5 HW & Test – Flashcards

question

What's the difference b/w selecting a member at random from a finite population and taking a simple random sample of size 1? a. A random member can't be selected from a finite population. b. Each member of the finite population doesn't have the same probability of being selected. c. The simple random sample is repeatable while the selection from the finite population isn't. d. There isn't a difference.

answer

d. There isn't a difference.

question

Rob, Dom, Clarice, Marco and John work for a publishing company. The company wants to send 2 employees to a stats conference. To be fair, the company decides that the 2 who get to attend will have their names drawn from a hat. This is like obtaining a simple random sample of size 2. A. Determine the sample space of the experiment. List all possible simple random samples of size n=2. Choose the correct answer. a. RD, RC, RM, RJ, DC, DM, DJ, CM, CJ, MJ b. RD, RC, RM, RJ, DC, DM, DJ, CM, CJ, MJ, RR, DD, CC, MM, JJ c. RD, RC, RM, RJ d. RD, RC, RM, RJ, DC, DM, DJ, CM, CJ, MJ, DR, CR, MR, JR, CD, MD, JD, MC, JC, JM B. What is the probability that Dom and Clarice attend the conference? C. What is the probability that Roberto attends the conference?

answer

A. a. RD, RC, RM, RJ, DC, DM, DJ, CM, CJ, MJ B. 0.1 C. 0.4

question

The table provides a frequency distribution for the number of rooms in this country's housing units (in thousands). Rooms // # of units 1 - 526 2 - 1,453 3 - 10,964 4 - 23,325 5 - 27,905 6 - 24,630 7 - 14,699 8+ - 17,277 A housing unit is selected at random. Find the following probabilities. A. Find the probability that the housing unit obtained has 4 rooms. B. Find the probability that the housing unit obtained has more than 4 rooms. C. Find the probability that the housing unit obtained has 1-2 rooms. D. Find the probability that the housing unit obtained has fewer than 1 room. E. Find the probability that the housing unit obtained has 1+ rooms.

answer

A. 0.193 B. 0.700 C. 0.016 D. 0 E. 1

question

The frequency distribution provies a certain condition prevalence frequency distribution for 61 regions. Condition (%) // Frequency 4-under 5: 7 5-under 6: 14 6-under 7: 18 7-under 8: 12 8-under 9: 5 9-under 10: 4 10-under 11: 1 A = event w/ prevalence of at least 8% B = event w/ prevalence of less than 7% C = event w/ prevalence of at least 5%, but less than 10% D = event that has a prevalence of less than 9% A. Determine the # of outcomes (regions) that constitute the event (not C). B. Determine the # of outcomes (regions) that constitute the event (A&B). C. Determine the # of outcomes (regions) that constitute the event (C or D). D. Determine the # of outcomes (regions) that constitute the event (C&B).

answer

A. Event (not C) has 10 regions. B. Event (A&B) has 0 regions. C. Event (C or D) has 63 regions. D. Event (C&B) has 32 regions.

question

The table provides a frequency distribution for the number of rooms in this country's housing units (in thousands). Rooms // # of units 1 - 5825 2 - 1,446 3 - 10,975 4 - 23,378 5 - 27,931 6 - 24,660 7 - 14,682 8+ - 17,247 A = event that the unit has at most 4 rooms B = event that the unit has at least 2 rooms C = event that the unit has b/w 4-6 rooms, inclusive D = event that the unit has more than 5 rooms Among the events A, B, C, D, identify the collections of events that are mutually exclusive. Are each of the following pairings of events mutually exclusive? - A & B: - A & C: - A & D: - B & C: - B & D: - C & D: Are each of the following given events mutually exclusive? - A,B, & C: - A,B, & D: - A,C & D: - B,C, & D: A,B,C, & D:

answer

A. - A & B: no - A & C: no - A & D: yes - B & C: no - B & D: no - C & D: no B. - A,B, & C: No - A,B, & D: No - A,C & D: No - B,C, & D: No A,B,C, & D: No

question

Suppose you hold 23 out of a total of 200 tickets sold for a lottery. The grand-prize winner is determined by the random selection of 1 of the 200 tickets. Let G be the event that you win the grand prize. Find the probability that you will win the grand prize. P(G) = ______

answer

P(G) = 23/200 = 0.115

question

The data represent the # of live multiple-delivery births (3+ babies) in a particular year for women 15-54 years old. Age // # Multiple Births 15-19: 94 20-24: 515 25-29: 1620 30-34: 2834 35-39: 1848 40-44: 371 45-54: 111 A. Determine the probability that a randomly selected multiple birth for women 15-54 years old involved a mother 30-39 years old. P(30-39) = ______ B. Determine the probability that a randomly selected multiple birth for women 15-54 years old involved a mother who wasn't 30-39 years old. P(not 30-39) = ______ C. Determine the probability that a randomly selected multiple birth for women 15-54 years old involved a mother who was less than 45 years old. P(less than 45) ~= _____ D. Determine the probability that a randomly selected multiple birth for women 15-54 years old involved a mother who was at least 20 years old. P(at least 20) =

answer

A. 0.633 B. 0.367 C. 0.985 D. 0.987

question

If P(E) = 0.60, P(E or F) = 0.80, and P(E and F) = 0.15, find P(F).

answer

0.35 P(E) = 0.6 P(E & F) = 0.15 P(E or F) = 0.8 Gen. Add'n Rule: P(E or F) = P(E) + P(F) - P(E&F) 0.8 = 0.6 + P(F) - 0.15

question

Info on the weights and years of experience for a football team was obtained. The given contingency table provides a cross-classification of those data. Compute the following conditional probabilities directly; that is, don't use the conditional probability rule. A player on the football team is selected at random. Complete a-e. .... | Rookie (Y1) | 1-5 (Y2) | 6-10 (Y3) | 10+ (Y4) | Total <200 (W1) 3 | 5 | 1 | 0 | 9 2-300 (W2) 8 | 13 | 15 | 8 | 44 300+ (W3) 0 | 8 | 6 | 0 | 14 Total 11 | 26 | 22 | 8 | 67 A. Find the probability that the player selected is a rookie. P(rookie) = _____ B. Find the probability that the player selected weighs under 200 lbs. P(weighs under 200) = ____ C. Find the probability that the player selected is a rookie, given that he weighs under 200 lbs. P(rookie|weighs under 200) = _____ D. Find the probability that the player selected weighs under 200 lbs, given that he is a rookie. P(weighs under 200|rookie) = ____ E. Interpret your answers in a-d in terms of percentages. Part A indicates that ___% of players are rookies. Part B indicates that ___% of players weigh under 200 lbs. Part C indicates that ___% of the players who weigh under 200 lbs are rookies. Part D indicates that ___% of the players who are rookies weigh under 200 lbs.

answer

A. 0.164 B. 0.134 C. 0.333 D. 0.273 E. 16.4%, 13.4%, 33.3%, 27.3%

question

For the month of February in a certain city, 91% of the days are cloudy. Also in the month of February in the same city, 65% of the days are cloudy and foggy. What is the probability that a randomly selected day in February will be foggy if it's cloudy?

answer

0.714 P(C) = 0.91 P(C & F) = 0.65 Conditional P Rule: P(F|C) = P(C&F) / P(C) = 0.65/0.91

question

Suppose A and B are 2 events. A. What does it mean for event B to be independent of event A? a. Event B is independent of A if P(A&B)=P(A or B) b. Event B is independent of A if P(A&B)=0 c. Event B is independent of A if P(A or B)=1 d. Event B is independent of A if P(B|A)=P(B) B. If event A and event B are independent, how can their joint probability be obtained from their marginal probabilities? a. The joint probability equals the product of the marginal properties; that is, P(A&B) = P(A)•P(B) b. The joint probability equals the sum of the marginal probabilities; that is, P(A&B)=P(A)+P(B) c. The joint probability equals the sum of the marginal probabilities minus the probability that either event will occur; that is, P(A&B)=P(A)+P(B)-P(A or B) d. The joint probability equals the product of the marginal probabilities minus the sum of the marginal probabilities; that is, P(A&B)=P(A)•P(B) - [P(A)+P(B)]

answer

A. d. Event B is independent of A if P(B|A)=P(B) B. Special Multiplication Rule (for 2 independent events) a. The joint probability equals the product of the marginal properties; that is, P(A&B) = P(A)•P(B)

question

A bag of 33 tulip bulbs contains 12 red ones, 11 yellow ones and 10 purple ones. A. What is the probability that 2 randomly selected tulip bulbs are both red? B. What is the probability that the 1st bulb selected is red, and the 2nd yellow? C. What is the probability that the 1st bulb selected is yellow and the 2nd red? D. What's the probability that 1 bulb is red and the other yellow?

answer

A. 0.125 This is a Conditional Probability Gen. Multiplication Rule [dependent events] = P(E&F)=P(E)•P(F|E) P(both red) = P(1st red) • P(2nd red|1st red) = (12/33) • (11/32) = 0.125 b/c there's 12 red roses so 12/33 for 1st draw. after that, there's only 11 red roses left and a total of 32 roses left, so 11/32 for 2nd draw B. 0.125 Also a Conditional Probability Gen. Multiplication Rule [dependent events] P(red then yellow) = P(1st red) • P(2nd yellow|1st red) = (12/33) • (11/32) b/c there's 12 red roses, so 12/33 for 1st draw. after that, there's still all 11 yellow roses left, but only 32 total roses left, so 11/32 for 2nd draw C. 0.125 Gen. Multiplication Rule P(yellow then red) = P(1st yellow) • P(2nd red|1st yellow) = (11/33) • (12/32) D. 0.25 There's 2 ways to pick 1 yellow and 1 red; yellow or red can be 1st. These events are MUTUALLY EXCLUSIVE. Addition Rule for ME events: P(1 red & 1 yellow): P(red then yellow) + P(yellow then red) = 0.125 + 0.125 = 0.25

question

A space shuttle is made up of 755 "critically 1" item must have 99.99% reliability, according to standards, meaning that the probability of failure for such an item is 0.0001. Determine the probability that A. None of the "critically 1" items would fail. B. At least 1 "critically 1" item would fail.

answer

A. 0.927 99.99% reliability = P(reliable) = 0.9999 These are INDEPENDENT events, Multiplication Rule: P(A)•P(B)•P(C)... = .9999^755 B. 0.073 P(not reliable) = 1 - P(reliable) = 1-0.927

question

A. What is a permutation? a. A permutation of r objects from a collection of m objects is any ordered arrangement of r of the m objects. b. A permutation of r objects from a collection of m objects is any unordered arrangement of r of the m objects. c. A permutation, NPn, is the # of possible samples of size n from a population of size N. d. A permutation is the product of the first k positive integers (counting numbers) and is denoted k!. B. What is a combination? a. A combination of r objects from a collection of m objects is any unordered arrangement of r of the m objects. b. A combination of r objects from a collection of m objects is any ordered arrangement of r of the m objects. c. A combination of a counting number is obtained by successively multiplying it by the next smaller counting number until reaching 1. d. A combination, NCn, is the number of possible samples of size n from a population of size N. C. What is the major distinction between the 2? a. Order matters in combinations but not in permutations. b. More combinations of r objects from a collection of m objects can be made than permutations. c. Order matters in permutations but not in combinations. d. Permutations can only be used when r is greater than 10.

answer

A. a. A permutation of r objects from a collection of m objects is any ordered arrangement of r of the m objects. B. a. A combination of r objects from a collection of m objects is any unordered arrangement of r of the m objects. C. c. Order matters in permutations but not in combinations.

question

A construction company builds new-home communities in several areas. In one subdivision, it offers 3 models (S, P, V) each in 3 different elevations (A, B, C). A. Draw a tree diagram depicting the possible choices for the selection of a home, including both model and elevation. a. common point, branches off to bond to S, P, V; each is bonded to A, B, C Outcome: SA, SB, SC, PA, PB, PC, VA, VB, VC b. common point, branches off to bond to A, B, S; each is bonded to C, V, P Outcome: AC, AV, AP, BC, BV, BP, SC, SV, SP B. Use the tree diagram to determine the total number of choices for the selection of a home, including both model and elevation.

answer

A. a. common point, branches off to bond to S, P, V; each is bonded to A, B, C Outcome: SA, SB, SC, PA, PB, PC, VA, VB, VC B. 9

question

Evaluate the given expression and express the result using the usual format for writing numbers (instead of scientific notation). 45P2

answer

= 1980 mPr = m! / (m-r)! = 45! / (45-2)! = (45•44•43•42...) / (43•42...) (everything gets cancelled out) = 45•44

question

Evaluate the given expression and express the result using the usual format for writing numbers (instead of scientific notation). 32C2

answer

496 mCr = m! / r!(m-r)! = 32! / 2!(32-2)! = 32! / 2•(30!) (everything 30•29 and beyond gets cancelled out) = 32•31 / 2

question

A hand of 5-card draw poker consists of an unordered arrangement of 5 cards from an ordinary deck of 52 playing cards. A. How many 5 card draw poker hands are possible? B. How many different hands consisting of three 9's and two 8's are possible? C. The hand in B is an example of a 4 of a kind. How many different 4 of a kinds are possible? D. Calculate the probability of being dealt a 4 of a kind.

answer

A. 2,598,960 UNordered = combo 52C5 = 52! / 5!(52-5)! B. 24 First find # of different ways to get three 9's: 4C3 = 4! / 3!(4-3)! = 4 Next, find # of diff ways to get two 8's: 4C2 = 4! / 2!(4-2)! = 6 Then, use basic counting rule --> 4•6 = 24 C. 3744 There's 13 different ways to pick the 3 card denomination • 12 different ways to pick the 2 card denomination • 24 ways to pick the 3 cards of one denomination and 2 cards of another domination = 3744 D. 0.00144 Use f/N rule: 3744/2598960

question

A student takes a T/F test consisting of 8 questions. Assume the student guesses at each question and find the probability that A. The student gets at least 1 question correct. B. The student gets a 50% or better on the exam.

answer

A. 0.996094 Complementation Rule: P(at least 1 correct) = 1 - P(none correct) Find P(none correct); use Combo Rule P(none) = 0 objects from a collection of 8 objects, so 8C0 = 8! / 0!(8-0)! = 1 Now use BCR to find total # poss. results of questions. There's 2 poss. results (correct/incorrect) for 8 questions, so 2^8 = 256 P(none) = 8C0 / 256 = 1/256 = 0.003906 P(at least one) = 1 - 0.003906 = 0.996094 B. 0.6368 1. Find P(getting exactly 4 questions correct); use Combo Rule: 8C4 = 8! / 4!(8-4)! = 70 Then divide by total # poss. for results of 8 questions -- 70/256 = 0.2734 = P(getting 4 questions correct) 2. Find P(5 ?s) = 8C5 = 8! / 5!(8-5)! = 56 Then divide...56/256 = 0.2188 3. Repeat: P(6) = 0.1094 P(7) = 0.0313 P(8) = 0.0039 4. Find the sum of all of those probabilities, and that's the probability of getting a 50% or better. 0.2734 + 0.2188 + 0.1094 + 0.0313 + 0.0039 = 0.6368

question

The table displays frequency distribution for the number of crew members on each shuttle mission over a 10 year period. Let X denote the crew size on a randomly selected shuttle from this time period. Crew size: 4 | 5 | 6 | 7 | 8 Frequency: 3 | 4 | 34|18|19 A. What are the possible values of the random variable X? B. Use random-variable notation to represent the event that the shuttle mission obtained has a crew size of 7. {___} C. Find P(X=5) D. Obtain the probability distribution of X.

answer

A. 4,5,6,7,8 B. {X = 7} C. 0.051 Suppose experiment has N poss. outcomes, all equally likely. N = ∑(all frequencies). An event that can occur in f ways has P f/N of occurring. N=78, f=4. P(X=5) = 4/78 = 0.051 D. P(X=4) = 0.038 P(X=5) = 0.051 P(X=6) = 0.436 P(X=7) = 0.231 P(X=8) = 0.244 A probability distribution is a listing of all the poss. values & corresponding P's of a DRV. To get the P distribution of X, determine the P of each value of the random variable X (f/N)

question

Determine whether the random variable is discrete or continuous. In each case, state the possible values of the random variable. A. Is the # of people w/ blood type A in a random sample of 31 people discrete or continuous? a. The random variable is continuous. The possible values are 0<=x<=31 b. The random variable is continuous. The possible values are x=0,1,2,...,31 c. The random variable is discrete. The possible values are 0<=x0 b. The random variable is continuous. The possible values are t=1,2,3,... c. The random variable is discrete. The possible values are t>0. d. The random variable is discrete. The possible values are t=1,2,3...

answer

A. d. The random variable is discrete. The possible values are x=0,1,2,...,31. B. a. The random variable is continuous. The possible values are t>0

question

The random variable X is the crew size of a randomly selected shuttle mission. Its probability distribution is shown. x | 2 | 3 | 4 | 5 | 6 | 7 | 8 P(X=x) |0.063|0.036|0.039|0.343|0.184|0.279|0.056 A. Find and interpret the mean of the random variable. µ = ______ B. Interpret the mean. a. As the # of obs., n, DEC, the mean of the obs. will approach the mean of the random variable. b. As the # of obs., n, INC, the mean of the obs. will approach the mean of the random variable. c. The observed value of the random variable will be less than the mean of the random variable in most obs. d. The observed value of the random variable will be equal to the mean of the random variable in most obs. C. Obtain the standard deviation of the random variable. σ = ______

answer

A. µ = 5.61 µ = ∑x•P(X=x) (2•0.063) + (3•0.036) + (4•0.039) + (5•0.343) + (6•0.184) + (7•0.279) + (8•0.056) B. b. As the # of obs., n, INC, the mean of the obs. will approach the mean of the random variable. C. σ = 1.477 sq rt{∑[x^2•P(x)] - µx^2} = sq rt{ [(2^2•0.063) + (3^2•0.036) + (4^2•0.039) + (5^2•0.343) + (6^2•0.184) + (7^2•0.279) + (8^2•0.056)] - (5.61^2)}

question

In a sporting event, the championship is won by the 1st team to win 4 games. The lengths of the championship games are given: # of games // Freq // Rel Freq 4 - 19 - 0.198 5 - 22 - 0.229 6 - 23 - 0.240 7 - 32 - 0.333 Let X denote the number of games that it takes to complete the championship games, and Y denote the number of games that it took to complete a randomly selected championship from among those considered in the table. A. Determine the mean and standard deviation of the random variable Y.

answer

A. µY = 5.708 µ = ∑x•P(X=x) First, multiply each possible value by its probability (relative frequency)(P(Y=y)) 4•0.198 = 0.792 5•0.229 = 1.145 6•0.240 = 1.44 7•0.333 = 2.331 Sum of them = 5.708 B. σY = 1.126 σ = sq rt{∑[y^2 • P(Y)] - µY^2} = sq rt{[(4^2•0.198) + (5^2•0.229) + (6^2•0.240) + (7^2•0.333)] - 5.708^2} Thus, the mean # of games played to win the championship is 5.708, with a standard deviation of 1.126.

question

A roulette wheel contains 38 numbers (18 red, 18 black, 2 green). When the roulette wheel is spun, the ball is equally likely to land on any of the 38 numbers. Suppose that you bet $7 on green. If the ball lands on a green number, you win $7; otherwise you lose your $7. Let X be the amount you win on your $7 bet. Then X is the random variable whose probability distribution is as follows. x | 7 | -7 P(X=x)|0.053|0.947 A. Find the expected value of the random variable X. b. Approximately how much would you expect to lose if you bet $7 on green 100 times? 1000 times?

answer

A. µ = -6.258 µ = ∑x•P(X=x) µ = (7•0.053) + (-7•0.947) = -6.258 Thus, on avg., you'll lose $6.258 per play, assuming you bet $7 each time. B. Multiply expected loss per game • # of times you play Bet $7 on green 100 times: expect to lose $625.80 Bet $7 on green 1000 times: expect to lose $6258.00

question

A factory manager collected data on the number of equipment breakdowns per day. From those data, she derived the probability distribution shown, where W denotes the number of breakdowns on a given day. w | 0 | 1 | 2 P(W=w)|0.75|0.15|0.10 A. Determine µw and σW. B. On average, how many breakdowns occur per day? C. About how many breakdowns are expected during a 1 year period, assuming 250 work days per year?

answer

A. µw = 0.35 σw = 0.654 B. 0.35 C. 87.5 (0.35•250)

question

Evaluate the given expression and express the result using the usual format for writing numbers (instead of scientific notation). 5!

answer

= 120

question

Simplify: (12) (7) (giant set of parentheses around both numbers)

answer

= 792 Binomial Coefficient: (n) = n! / x!(n-x)! (x) = 12! / 7!(12-7)!

question

Shown are the # of trials and success probability for some Bernoulli trials. Let X denote the total number of successes. n=4, and p=0.7 A. Determine P(X=2) using the binomial probability formula. B. Determine P(X=2) using a table of binomial probabilities. C. Compare this answer to part A. a. The 2 probabilities are ~ equal at 3 decimal places. b. The probability from part A is much larger than the probability from part B. c. The 2 probabilities are exactly equal at 3 decimal places. d. The probability from part B is much larger than the probability from part A.

answer

A. P(X=2) = 0.265 Binomial Probability Formula: P(X=x) = (n)p^x•(1-o)^[n-x] (x) B. 0.265 C. c. The 2 probabilities are exactly equal at 3 decimal places.

question

The probability is 0.45 that a traffic fatality involves an intoxicated or alcohol-impaired driver or non-occupant. In 10 traffic fatalities, find the probability that the number, Y, which involve an intoxicated or alcohol-impaired driver or non-occupant is... Aa. The probability that exactly 3 traffic fatalities involve an intoxicated or alcohol-impaired driver or non-occupant is _____. Ab. The probability that at least 3 traffic fatalities involve an intoxicated or alcohol-impaired driver or non-occupant is _____. Ac. The probability that at most 3 traffic fatalities involve an intoxicated or alcohol-impaired driver or non-occupant is _____. B. The probability that between 2-4 traffic fatalities, inclusive, involve an intoxicated or alcohol-impaired driver or nonoccupant is _____. Ca. The mean of Y is _____. Cb. Interpret the mean. a. In every 10 traffic fatalities, exactly this many will involve an intoxicated or alcohol-impaired driver or nonoccupant. b. On average, of 10 traffic fatalities, this many will involve an intoxicated or alcohol-impaired driver or nonoccupant. c. On average, of this many traffic fatalities, 1 will involve an intoxicated or alcohol-impaired driver or nonoccupant. D. The standard deviation of Y is _____.

answer

A. a) Exactly 3: p(Y=3) = 0.1665 "Success" = fatality, p=0.45, n=10 Binomial Probability Formula: p(Y=y)= (n...y) • p^y • (1-p)^n-y = [10! / 3!(10-3)!] • (0.45)^3 • (1-0.45)^10-3 = 0.166478293 b) At least 3: p(Y=3+) = 0.9004 Find p(Y=0,1,2) then subtract from 1. p(Y=2) = 0.076302551 p(Y=1) = 0.02072415 p(Y=0) = 0.002532952 c) At most 3: p(Y=0-3) = 0.2660 Use the values calculated above, and add. ∑p(Y=3,2,1,0) B. Between 2-4: p(∑[Y=2,3,4]) = 0.4811 Find p(Y=4) = 0.238366647 Add p(Y=2,3,4) Ca. µ of Y = 4.5 µ of BRV = (n trials)(p of successes) = (10)(0.45) Cb. b. On average, of 10 traffic fatalities, this many will involve an intoxicated or alcohol-impaired driver or nonoccupant. D. σ = 1.57 Standard Deviation of Binomial Random Variable: σ = sq rt{n • p • (1-p)} σ = sq rt{10 • 0.45 • 0.55)}

question

According to a health publication, 15.7% of persons under the age of 65 have no health insurance coverage. Suppose that 4 persons under the age of 65 are randomly selected. A. Complete the table to determine the probability distribution for the number, X, who have no health insurance coverage. x | P(X=x) 0 | 1 | 2 | 3 | 4 | B. The mean of X is ____. C. Choose the correct interpretation of the mean: a. On average, we'd expect this many people out of 4 under the age of 65 to have health insurance coverage. b. On average, we'd expect this many people out of 4 under the age of 65 to have no health insurance coverage. c. On average, we'd expect this many people out of 1 under the age of 65 to have no health insurance coverage.

answer

A. p(X=0) = 0.5050 p(X=1) = 0.3762 p(X=2) = 0.1051 p(X=3) = 0.0130 p(X=4) = 0.0006 Binomial Probability Formula "success" = have no insurance, p = 0.157, q=0.843 B. µ = 0.628 C. b. On average, we'd expect this many people out of 4 under the age of 65 to have no health insurance coverage.

question

For each of the probability histograms of binomial distributions, specify whether the success probability is less than, equal to, or greater than 0.5 a) [right skewed] points at: (0,0.125) (1,0.3) (2,0.33) (3,0.19) (4,0.05) (5,0.01) b) [symmetrical] points at: (0,0.25) (1,0.15) (2,0.32) (3,0.32) (4,0.15) (5,0.025)

answer

A. The success probabiity, p, is less than 0.5 B. The success probability, p, is equal to 0.5

question

The following is a probability distribution for the # of Mexican-American jurors, X, on a 12 person jury. The jury was randomly selected from a population in which 70% of the people are Mexican-Americans. x | P(X=x) 0 | 0.000 1 | 0.000 2 | 0.000 3 | 0.001 4 | 0.008 5 | 0.029 6 | 0.079 7 | 0.158 8 | 0.231 9 | 0.240 10 | 0.168 11 | 0.071 12 | 0.014 A. Use the special addition rule and the probability distribution to determine P(X≥7) B. Use the special addition rule and the probability distribution to determine P(X=3). C. Use the special addition rule and the probability distribution to determine P(5≤X≤7).

answer

question

Suppose 11 cars start at a car race. In how many ways can the top 3 cars finish the race?

answer

990 Permutations rule; order matters! 11P3 = (11!) / (11-3)!

question

A recent census found that 52.2% of adults are female, 10.6% are divorced, and 6.2% are divorced females. For an adult selected at random, let F be the event that the person is female, and D be the event that the person is divorced. A. Obtain P(F), P(D), and P(F&D). B. Determine P(F or D). C. Find the probability that a randomly selected adult is male.

answer

A. P(F) = 0.522 --- 52.2% are female, change to a decimal P(D) = 0.106 --- 10.6% are divorced, change to a decimal P(F&D) = 0.055332 --- Special Multiplication Rule; events are independent; P(A&B) = P(A)•P(B) RIGHT ANSWER: 0.062 B. P(F or D) = 0.572668 --- General Addition Rule: P(E or F) = P(E) + P(F) - P(E&F) RIGHT ANSWER: 0.566 C. P(male) = 0.478 --- Complementation Rule: P(not E) = 1 - P(E)

question

The owner of a stereo store wants to advertise that he has many different sound systems in stock. The store carries 8 different CD players, 7 different receivers, and 10 different speakers. Assuming a sound system consists of one of each, how many different sound systems can he advertise?

answer

560 8•7•10

question

According to an article, 47% of adults have experienced a breakup at least once during the last 10 years. Of 9 randomly selected adults, find the probability that the number, X, who have experienced a breakup at least once during the last 10 years is: A. exactly 5; at most 5; at least 5 B. at least 1; at most 1 C. Between 2-4, inclusive D. Determine the probability distribution of the random variable X. Complete the table: x | P(X=x) 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |

answer

A. a) Exactly 5: 0.0640 RIGHT ANSWER: 0.2280 --- P(X=x) = [n! / (x!(n-x)!)] • p^x • q^n-x Find P(X=5), p = 0.47, q = 0.53, n = 9 b) At most 5: 0.6375 RIGHT ANSWER: 0.8015 --- Find P(X=0,1,2,3,4,5) and ∑ --- P(X=0) = 0.003299764 --- P(X=1) = 0.026335849 --- P(X=2) = 0.093417729 --- P(X=3) = 0.193298319 --- P(X=4) = 0.257123236 c) At least 5: 0.2626 --- Find P(X=5,6,7,8,9) and ∑ --- P(X=6) = 0.134801288 --- P(X=7) = 0.051231756 --- P(X=8) = 0.011357984 --- P(X=9) = 0.00111913 RIGHT ANSWER: 0.4265 B. a) At least 1: 0.9967 --- Do 1 - P(X=0) = 0.996700236 b) At most 1: 0.0296 -- Do P(X=0) + P(X=1) = 0.029635613 C. 0.5438 ∑P(X=2,3,4) D. x | P(X=x) 0 | 0.0033 1 | 0.0263 2 | 0.0934 3 | 0.1933 4 | 0.2571 5 | 0.0640 RIGHT ANSWER: 0.2280 6 | 0.1348 7 | 0.0512 8 | 0.0114 9 | 0.0011

question

These are the possible outcomes when a couple has 3 children. 1st | 2nd | 3rd B - B - B B - B - G B - G - B B - G - G G - B - B G - B - G G - G - B G - G - G Find the probability of: A. Among 3 children, there are exactly 3 boys. B. Among 3 children, there're exactly 0 boys. C. Among 3 children, there's exactly 1 boy.

answer

A. 1/8 B. 1/8 C. 3/8

question

You draw a card at random from a standard deck of 52 cards. Find the following conditional probabilities. A. The card's a diamond, given that it's red. B. The card's red, given that it's a diamond. C. The card is a 10, given that it's red. D. The card is a king, given that it's a face card.

answer

Conditional Probability Rule: P(B|A) = P(A&B) / P(A) a. 1/2 (13/52) / (26/52) b. 1 (13/52) / (13/52) c. 1/13 (2/52) / (26/52) d. 1/3 (4/52) / (12/52)

question

Decide if the events are mutually exclusive. Event A: Randomly selecting an animal with green eyes. Event B: Randomly selecting an animal with brown eyes. a. Yes, b/c an animal w/ green eyes can't have brown eyes. b. No, b/c an animal w/ green eyes can't have brown eyes. c. No, b/c an animal w/ green eyes can have brown eyes. d. Yes, b/c an animal w/ green eyes can have brown eyes.

answer

a. Yes, b/c an animal w/ green eyes can't have brown eyes.

question

Suppose 80% of kids who visit a doctor have a fever, and 40% of kids with a fever have sore throats. What's the probability that a kid who goes to the doctor has a fever and a sore throat?

answer

0.32 General Multiplication Rule P(A&B) = P(A) • P(B|A) = 0.8 • 0.4

question

The table provides a freq. dist. for the # of rooms (in thousands) in this country's housing units. Rms | # of units 1 | 534 2 | 1,424 3 | 10,959 4 | 23,365 5 | 27,907 6 | 24,694 7 | 14,603 8+ | 17,221 A = event that the unit has at most 4 rooms B = event that the unit has at least 2 rooms C = event that the unit has 5-7 rooms, inclusive D = event that the unit has 7+ rooms A. Determine the # of outcomes (housing units) that constitute the event (not A). B. Determine the # of outcomes (housing units) that constitute the event (A&B). C. Determine the # of outcomes (housing units) that constitute the event (C or D).

answer

A. 84,425 B. 35,748 C. 84,425

question

The table provides a freq. dist. for the # of rooms (in thousands) in this country's housing units. Rms | # of units 1 | 559 2 | 1,489 3 | 10,915 4 | 23,347 5 | 27,949 6 | 24,612 7 | 14,672 8+ | 17,230 A housing unit is selected at random. Find: A. the probability that the housing unit obtained has 4 rooms. B. the probability that the housing unit obtained has more than 4 rooms. C. the probability that the housing unit obtained has 1 or 2 rooms. D. the probability that the housing unit obtained has fewer than 1 room. E. the probability that the housing unit obtained has 1 or more rooms.

answer

A. 0.193 23347 / 120773 B. 0.699 (27949 + 24612 + 14672 + 17230)/120773 C. 0.017 (559 + 1489) /120773 D. 0 E. 1

question

The random variable X is the # of color TV sets owned by a randomly selected household with an annual income between $15k-$29,999k. Its probability distribution: x | P(X=x) 0 | 0.065 1 | 0.278 2 | 0.214 3 | 0.226 4 | 0.217 Aa. Find the mean. Ab. Interpret: a. The observed value of the random variable will be less than the mean of the random variable in most observations. b. The observed value of the random variable will be equal to the mean of the random variable in most observations. c. As the # of observations, n, DEC, the mean of the observations will approach the mean of the random variable. d. As the # of observations, n, INC, the mean of the observations will approach the mean of the random variable. B. Obtain the standard deviation of the random variable. C. Draw a probability histogram for the random variable. Choose the correct graph. a. (0,.05) (1,0.29) (2,.2) (3,.21) (4,.2) b. (0,.29) (1,.22) (2,.05) (3,.21) (4,.21) c. (0,.21) (1,.22) (2,.21) (3,.29) (4,.07) d. (0,.21) (1, .22) (2,.21) (3,.07) (4,.29)

answer

Aa. µx = 2.252 Mean of Discrete Random Variable: µ = ∑(x•P(X=x)) µ = (0•0.065)+(1•0.278)+(2•0.214)+(3•0.226)+(4•0.217) Ab. d. As the # of observations, n, INC, the mean of the observations will approach the mean of the random variable. B. σ = 1.252 = √{∑[x²•P(x)] - µx²} = √{[(0²•0.065) + (1²•-.278)+(2²•0.214) + (3²•0.226) + (4²•0.217)] - (2.252²)} C. a. (0,.05) (1,0.29) (2,.2) (3,.21) (4,.2)

question

Each of the digits 0,1,2,3,4,5,6,7,8,9 are written on a slip of paper, and the slips are placed in a hat. If 3 slips of paper are selected at random, find the probability that the 3 numbers are greater than 4.

answer

1/12 5C3 / 10C3 = 10/120

question

2 cards are drawn at random from an ordinary deck of 52 cards. Determine the probability that both cards are spades if A. The 1st card is replaced before the 2nd card is drawn. B. the 1st card isn't replaced before the 2nd card is drawn.

answer

A. 0.063 (13/52)•(13/52) B. 0.059 (13/52)•(12/51)

Literature
Prejudice
Statistics
Writing

Types of Evidence Used In Persuasive and Argumentative Writing – Flashcards 10 terms
Alden Wolfe

10 terms
Preview

Types of Evidence Used In Persuasive and Argumentative Writing – Flashcards

question

Persuasive Writing

answer

Presents reasons and examples to influence action or thought

question

Argument

answer

A statement, belief, or claim based on reason or evidence

question

Claim

answer

An idea an author tries to prove or defend an argument

question

Bias

answer

Prejudice in favor of something; something doesn't weigh both sides

question

Evidence

answer

The support or proof that backs an argument

question

Facts

answer

statements that can be proven true

question

Statistics

answer

Facts in number form

question

Anecdotes

answer

A short, amusing, and interesting story about a real thing

question

Expert Opinion

answer

A person's opinion who has knowledge or experience in a field

question

Direct Quotation

answer

The exact words of someone else woven into your writing using quotation marks

Education
Ethnic Studies
Psychology
Statistics

Understanding Psychology Major – Flashcards 34 terms
Jonathan Walsh

34 terms
Preview

Understanding Psychology Major – Flashcards

question

Once you have met the requirements to declare the major you must visit ATLAS to declare the psychology major.

answer

TRUE

question

The psychology major has over 1200 declared psychology majors

answer

TRUE

question

To declare the psychology major you need

answer

PSY 100, PSY 210, PSY 22 and have a C or better with a cumulative GPA of 2.5 or above

question

Workshops and help for students on Probation and Disqualified student help. Academic advising for undeclared students and other colleges

answer

The University Center for Undergraduate Advising in the Horn Center room 103

question

Academic Advising or Psychology Major, College of Liberal Art's majors & minors, GE, capstones, units, GPAs, class planning, double counting, and CSULB graduation requirements

answer

ATLAS

question

Department specific items, for Psychology: Psychology course equivalents and getting psychology credits for studying abroad

answer

PRO advisors

question

General Psychology related questions, course info, psychology course syllabi, grad school info, jobs, internships, and 301 hep

answer

PRO room 206

question

You can drop by the PRO in room PSY 206 for:

answer

questions about the psych department resources capstones and GE questions graduate school in psych resources PSY 301 help academic advising course syllabi from psych courses

question

If you were looking for opportunities for Research experience where could you look?

answer

the faculty interests section o he psych major handbook the psych department website in PRO

question

When looking for research opportunities you should focus on tunered or tenure-track faculty members

answer

TRUE

question

The College of Liberal Arts Advising Center called ATLAS is in Ph1 room 104 is open Monday-Friday and you can drop in or make an appointment to see them about Psychology major requirements, declaring the psychology major, GE requirements, units, GPAs, or other majors and minors in the College of Liberal Arts. They do all the academic advising for psychology students.

answer

TRUE

question

To graduate from CSULB you need:

answer

at least 120 total units 3 upper division Capstone courses at least a 2.0 in all four GPAs (overall, CSULB, major and upper division major GPA) to complete all major requirements to complete all lower division GE courses or have your GE certification

question

Minors usually require at least ____ units.

answer

20

question

30 units out of your 120 total units needed must be taken in Residency, this means:

answer

at least 30 out of your 120 units must be taken at CSULB

question

You must pass the Writing Proficiency Exam (WPE) or take a writing course at CSULB before graduating to meet the GWAR writing requirement.

answer

TRUE

question

You must file a request to graduate (found online at the enrollment services website) at least:

answer

After 90 units and before the enrollment services deadline for graduation terms

question

PSY 241- Psychobiology is required for:

answer

applying to the psychology major taking PSY 331, 332, 333 and all the other group one psychology courses psychology major requirements for graduation psychology minor requirements for graduation applying to the psychology minor

question

All departments handle prerequisites differently. In the psychology department you can take a psychology course without the prerequisites.

answer

CSULB catalog in the Psych Major Handbook on the Psy Major & minor checksheets

question

If you register for a psychology course and do not have the prerequisites:

answer

You can and most likely will be dropped from he class by the instructor once the semester starts You will still have to take the prereqs curse for the psych major or minor You will not be prepared for the course and will fall behind

question

If you plan on going to Graduate School in Psychology, you shoud plan on taking: (check all that apply)

answer

PSY 310 Intermediate Statistics, 411 Experimental Design & analysis, and 412 Multivariate Statistics PSY 314 Assessment and/or 315 Testing 400 level research courses

question

At CSULB a grade of D is considered a passing grade. Only the Psychology Department requires you to have a grade of C or better in PSY 100, 210, and 220 for admission to the major.

answer

TRUE

question

The last category of the psychology major requirements requires you to take 2 courses from other departments. One must be from the list of __________ courses. The other must be upper division (300 level or above) from any of the approved departments.

answer

Ethnic Studies

question

You can get a list of the approved ethnic studies courses from: (check all that apply)

answer

The Psychology Department website The main psychology department office (in PSY 100) Inside the Psychology Major Handbook The University Center for Undergraduate Advising in the Horn Center, room 103.

question

All courses take at a Community or Junior College are considered Lower division. Lower division community college courses CANNOT be used for upper division (300 level or above) CSULB courses. You can check Assist.org or in the Psychology Major Handbook for transfer equivalents at CSULB.

answer

TRUE

question

At CSULB you can take PSY 100, 210, and 220 all in the same semester.

answer

FALSE

question

If you are declared as a "pre-major" you will have to declare a "real" major by 60 units or enrollment services will put a hold on your account until you declare a major.

answer

TRUE

question

The Psychology Student association (PSA) and Psi Chi Psychology Honor Society: (check all that apply)

answer

meet together every other week put on Psych Day look good on vitas and resumes for applying to graduate school and jobs

question

Which group of psychology courses are open to Psychology majors only? (Meaning you must be declared as a psychology major to take these courses)

answer

400 level courses

question

Students at CSULB are limited to ____ units of repeating.

answer

28

question

Grade Forgiveness

answer

16 units

question

Total number of units you need to graduate with a psych BA at CSULB

answer

120 units

question

total number of units you are allowed to withdraw from

answer

18 units

question

total number of unis you are allowed to repeat

answer

28 units

question

grade averaging

answer

12 units

Psychometrics
Statistics
True False Questions
Worth The Effort

EDFL 456: Test 2 – Flashcards 214 terms
Chloe Barnes

214 terms
Preview

EDFL 456: Test 2 – Flashcards

question

What are the results going to be used for

answer

Which of the following is the first consideration in planning a test?

question

Formative

answer

Which of the following assessment types should be used to evaluate student progress learning?

question

Placement

answer

A type of pretest is?

question

Improve validity

answer

Table of specifications?

question

Summative

answer

To certify student accomplishment

question

Factual knowledge

answer

Failure to use proper specifications for tests and assessments will result in overemphasis in?

question

Importance of objectives

answer

Distribution of items and tasks ?

question

D

answer

If a class test measure

question

Decrease validity and increase reliability

answer

Constructing test items from single cell to two-way table

question

Test blueprint

answer

Table of specs

question

How much time spent on it in class

answer

Weight assigned to instructional objective in table?

question

Extended and restrictive

answer

Two major classes of essay?

question

Require only paper and pencil

answer

One advantage of supply items of performance based task?

question

Validity

answer

Which characteristic of test have to be increased following the principle of measuring learning outcome most directly

question

Short Answer

answer

Measure recall of important historical dates?

question

Extended-response performance tasks

answer

To measure integration and application of critical concepts?

question

True and False

answer

Which types of objectives test items is likely to be most appropriate for measuring the objective "distinguishes between fact and opinion?

question

Provide clues to misunderstandings

answer

One advantage of the multiple choice item over other selection type items?

question

Nature of the learning tasks

answer

For a criterion-referenced interpretation the difficulty should be determining by which of the following factors?

question

Include more higher level learning outcomes

answer

The most desirable way to increase the difficulty of classroom test is to?

question

Validity

answer

Removing clues to the answer from test items is most likely to improve the tests?

question

Sampling

answer

Using specifications when constructing test items and assessment tasks most likely improves?

question

Number of items on the test

answer

Substituting multiple choice items for extended performance tasks increases?

question

agreed upon by experts

answer

The answer to an item in a classroom test should be one that is?

question

The most direct measure of the intended learning outcome

answer

the most basic principle in selecting the type of test items and assessment tasks is to select the types that are?

question

Short answer

answer

Which of the following item types is classified as a supply-type item?

question

True false

answer

Which of the following item types would provide the highest score based on guessing alone?

question

True false

answer

Which of the following item types would be most effective for measuring the ability to distinguish between factual statements and opinions?

question

True false

answer

Which of the following item types is difficult to assess students higher order thinking skills?

question

Computational skills

answer

Sort answer test items are clearly superior to matching or true false meaning?

question

Scoring

answer

Short answer major shortcoming

question

The author of (book title) is?

answer

Most well written short answer?

question

A test that is reliable is not necessary _______ or useful

answer

Which of the following is the most well-written short answer item?

question

Lowers reliability

answer

In correcting a short answer test to measure students knowledge of specific principles a teacher deducted one point from the total score for each misspelled word. How would this procedure affect test results?

question

Grid-in

answer

In large scale math testing programs many of the advantages of supply type items can be maintained by using which item?

question

They are time consuming to score

answer

Which of the following is a limitation of short answering?

question

Misinformation could lead to the correct answer

answer

All whales are mammals because they are large...asking students to mark the previous statement...would be considered poor testing practice because?

question

A rising barometer forecasts fair weather

answer

Which of the following is the most well written true false?

question

a. Specific determiners

answer

42. Absolute terms like all or non that provide clues in true false statements are known as?

question

a. Increases the number of items

answer

A true false test can be made more reliable if a teacher does which of the following?

question

a. Alaska is never hot in the summer

answer

44. Which of the following true false items statements has a specific determiner?

question

a. Knowledge

answer

45. Matching items are most useful for measuring learning outcomes at which of the following levels?

question

a. Multiple choice

answer

46. The matching item is a modified form of the?

question

a. Relate

answer

47. One difficulty in constructing matching items is that it is difficult to find material tat requires students to?

question

a. Homogenous

answer

48. A difficulty in constructing matching items is finding material that is?

question

a. Using responses more than once

answer

49. Guessing on a matching item can be reduced by doing which of the following?

question

a. Rote learning

answer

50. Excessive use of matching items will most likely result in overemphasis on which of the following?

question

a. Matching

answer

51. Which of the following types of items has the greatest chance of measuring irrelevant material?

question

a. False

answer

52. One way to cut down on the assessment of irrelevant information in matching items is to write them first as true false questions

question

53. One problem with true false items is that when a false item is correct it does not measure whether the student actually knows the information that makes the item true? a. Agree

answer

53. One problem with true false items is that when a false item is correct it does not measure whether the student actually knows the information that makes the item true?

question

a. Short answer

answer

54. In which of the following types of questions would interrater reliability probably be an issue?

question

a. Reduce validity - testing for spelling not content

answer

55. Discuss why a teacher would likely not take off for spelling when scoring a short answer question

question

a. Higher order thinking

answer

57. The interpretive item is probably..

question

a. measurement of complex learning outcome

answer

58. Using interpretive exercises results in more effective

question

a. Should be in harmony with learning outcomes

answer

59. The introductory material used should include?

question

a. Interpretive measures more complex learning outcomes

answer

60. One advantage of interpretative exercise over the single multiple choice item?

question

a. Provides a more structured task

answer

61. One advantage of the interpretive exercise over performance based assessment tasks is that the interpretive

question

a. Reading

answer

62. Which of the following "enabling skills" would most likely to lower the validity of an interpretive exercise?

question

a. Validity

answer

63. Requiring students to recall an excessive amount of factual information in order to solve and interpretive exercise can result in lower

question

a. Including items that can be answered on the basis of general knowledge

answer

64. Which of the following is common error made by test designers in constructing interpretive?

question

a. Key type and multiple choice

answer

65. Which of the following types of test items are most commonly used with interpretive?

question

a. Irrelevant factual information

answer

66. The use of interpretive exercises to measure complex learning outcomes reduces the influence of what?

question

a. It is new to the students

answer

67. The introductory material in the interpretive exercise is most effective if?

question

a. To detect invalid inferences

answer

68. The interpretive exercise is especially useful for educators because it assists in measuring the ability?

question

a. They require more than the recall of information to answer

answer

69. The test items in an interpretive exercise are most effective if they include which of the following?

question

a. Visual

answer

70. When teaching very young students it is best to use material that is?

question

a. Higher interrater reliability

answer

71. When compared to essay questions, interpretative exercises possess?

question

a. Attempt to answer the questions without the introductory material

answer

72. A simply method for checking the adequacy of an interpretive exercise is to do which of the following?

question

a. Constructing them

answer

73. Which of the following factors makes it difficult use interpretive exercises on a test?

question

a. Produce a product

answer

74. The interpretive exercise is least useful for measuring the ability to?

question

a. Poorly constructed and invalid

answer

75. If the higher achieving student in class can answer the questions on an interpretive exercise without looking at the introductory material but the lower achieving students cant - the exercise is likely?

question

a. Choosing a passage that is relatively brief

answer

76. Which of the following would be considered sound principles for constructing an interpretive exercise based on a reading passage?

question

a. Short-term memory

answer

77. Keeping the introductory materials on an interpretive exercise relatively brief would assist students who may be experiences issues of?

question

a. Answering reading comprehension questions

answer

78. Which of the following would likely be a legitimate use of the interpretive exercise?

question

a. Lower and grade level

answer

79. Which of the following should probably be the relationship between introductory materials in a science curriculum interpretive exercise and reading level of students?

question

a. Validity

answer

82. The use of some essay questions in a classroom test will probably improve the assessments?

question

a. Synthesis

answer

83. For which of the following types of learning outcomes is the essay most useful?

question

a. Determining the scoring procedures in adavance

answer

84. Which of the following is useful for improving essay testing?

question

a. Bboth are useful in both formative and summative assessment

answer

85. Which of the following characteristics is shared by both objective tests and essay tests?

question

a. Difficult to score

answer

86. One major problem in using essay qestions to evaluate learning is?

question

a. Organizing and integrating ideas is important

answer

87. Essay questions should be used in achievement tests when?

question

a. Development of an argument

answer

88. Essay questions are more appropriate than multiple choice items when learning outcome calls for?

question

a. Integrate information

answer

89. Essay are more appropriate than objective when measuring?

question

a. Limited sampling

answer

90. Which is a serious limitation of an essay test?

question

a. Complex learning outcomes are being assessed

answer

91. An extended response essay is better than restricted if?

question

a. Specific information needs to be supplied by the student

answer

92. A restricted response essay question is better than extended response?

question

a. Identifying the meaning of concepts

answer

93. For which of the following learning outcomes would objective items be better than essay?

question

a. Using the rating method for extended response questions

answer

94. Which is a sound essay grading procedure?

question

a. Validity

answer

95. Deducting points for neatness on essay responses will have the greatest influence on which of the following?

question

a. Prepare a model answer in advance

answer

96. Which of the following is a desirable practice for using restricted response essay?

question

a. Clearly indicate the nature of the desired answer

answer

97. Which test construction procedures is most likely to result in valid responses to extended response essay questions?

question

a. Grade content and spelling separately

answer

98. Which of the following is desirable practice for grading essay?

question

a. Extended response

answer

99. In order to assess students ability to express themselves creatively in writing?

question

a. Basis of comparing students is undetermined

answer

100. Presenting students with several essays to respond to?

question

a. Having a second competent scorer grade the paper (interrater reliability)

answer

101. Which of the following would most likely improve the scoring of an essay answer on a test?

question

a. Ability to formulate problems

answer

104. Performance based are more effective than MC in

question

a. Both process and product

answer

105. Advantage of performance based assessment...

question

a. Lengthy administration time

answer

106. Problem of performance based assessment

question

a. When the problems are structured so the model performances can be constructed

answer

107. Restricted response performance based better than extended response?

question

a. Provide students with valuable learning opportunities

answer

108. Best justification for large amount of time required for performance

question

a. Reduces validity

answer

109. Dependecnce of task performance on skills that are irrelevant

question

a. Severity error

answer

110. A teacher who rates all performances lower

question

a. Rate performances on one task for all students before rating performance on another task

answer

113. Rating product of student performances it is best for educators

question

a. To provide diagnostic information to students

answer

114. Analytic scoring is better than hostic scoring when an educator is trying?

question

a. Purposeful

answer

116. Student portfolios are distinguished from file folders

question

a. The ease wthey are integrated with instruction

answer

117. Strength of portfolios

question

a. Lack standardization needed for comparability

answer

118. Potential weakness in porfolios

question

a. They are labor intensive

answer

119. Major obstacle for portfiolio

question

a. Haphazard collection of student work

answer

120. Misconception of portfolios

question

a. Specified in portfolio guidelines

answer

121. Types of work appropriate for portfolio

question

a. Formative eval

answer

122. Which eval criteria is most useful analytic scoring

question

a. Assessment of factual knowledge

answer

123. Least likely to be achieved using portfolios

question

a. Holistic evaluation criteria

answer

124. Argument of summative grades?

question

a. Primary purpose of instruction

answer

125. Collaborative assessment in portfoilios

question

a. disagree

answer

127. best to evaluate on appearance

question

a. Gives parents insight into what goes on in the classroom

answer

128. which is an advantage of communicating portfolio results with parents?

question

a. Will students receive individual or group grade

answer

129. Which of the following is a particular issue tat educators need to consider when portfolios in group

question

Essay questions are placed last

answer

When arranging items in a test, it is best to ensure which of the following?

question

correct for guessing

answer

If test directions instruct students to "answer every item," it is not recommended that educators

question

number of alternatives

answer

The effect of guessing on scores can best be reduced on a multiple-choice test by increasing which of the following?

question

more high-scoring students

answer

A test item has positive discriminating power when answered correctly by

question

50%

answer

On a test of 50 students, if 25 students answered an item correctly, the item difficulty is

question

70%

answer

If item analysis data shows that an item was answered correctly by 8 out of 10 students in the upper group and 6 out of 10 students in the lower group, the difficulty of the test item is

question

the small number of students

answer

Which of the following is a major limitation of using item analysis procedures with the typical classroom test?

question

50%, .60.

answer

If 8 out of 10 students in the upper group and 2 out of 10 students in the lower group answer an item correctly, then the difficulty and discriminating power of the item would be

question

obtained low scores

answer

A distracter in a multiple-choice item is judged good if it attracts more students who have

question

True

answer

It is probably a sound motivational procedure for the teacher to announce that an upcoming test is high stake for students. (True or False)

question

Agree

answer

One good method for discouraging cheating is to proctor an exam by moving around the room. (Agree or Disagree)

question

False

answer

If paper costs are a factor, educators can reduce the print size of test questions. (True or False)

question

Agree

answer

It is good practice to not break up a test item an continue it on the next page. (Agree or Disagree)

question

True

answer

It is good practice to have a colleague check test item for bias. (True or False)

question

improve student learning

answer

The main purpose of a marking and reporting system should be to accomplish which of the following?

question

include too many different elements

answer

A serious limitation of reporting progress with a single letter grade only is that letter grades

question

achievement

answer

When a letter grade (A, B, C, D, F) is used to report student progress, the grade should be based on which of the following?

question

instructional objectives

answer

A school's marking and reporting system should be based on which of the following?

question

adequate assessment of students

answer

An effective grading and reporting system is based on which of the following?

question

checklist of objectives

answer

Which of the following methods is most useful for overcoming learning difficulties?

question

multiple marking

answer

Assigning grades that represent a pure measure of achievement is most feasible with which of the following systems?

question

it doesn't assess gradation of learning

answer

Which of the following is a major disadvantage of using the pass-fail system?

question

encourages students to explore new areas of study

answer

One advantage of the pass-fail grading system in elective courses is that it

question

they lack common meaning from one teacher to another

answer

Which of the following is the most serious limitation of the traditional letter grade as a means of reporting student progress?

question

spread of scores on each test

answer

When weighting sets of test scores to obtain a composite score for assigning grades, the weighting should be based on which of the following?

question

level of performance

answer

Absolute grading would require information concerning a student's

question

beginning by discussing the student's weaknesses

answer

During parent-teacher conferences, which of the following actions should be avoided?

question

summarize and plan a course of action

answer

Near the end of a parent-teacher conference, it is most important for the teacher to

question

percentile rank

answer

Which of the following is the most useful score for reporting standardized test results to parents?

question

True

answer

Grades such as T-scores are based on variability. (True or False)

question

Agree

answer

Sending letters home to the parent or guardian as a report card assumes that the adult is able to understand the vocabulary on the report. (Agree or Disagree)

question

True

answer

It is appropriate to collapse achievement and effort into a single letter grade. (True or False)

question

Agree

answer

Record keeping of student grades may be streamlined by using computer spreadsheets. (Agree or Disagree)

question

the score is interpreted without more information

answer

A student in grade 6 earned a raw score of 50 on an achievement test. Which of the following interpretations is most justified?

question

His percentage-correct score is 91

answer

Brent earned a score of 91 on a 100-item achievement test. Which of the following interpretations is most justified?

question

describing the nature of the individual's performance

answer

Which of the following best illustrates a criterion-referenced interpretation?

question

there are enough items for each interpretation

answer

When making criterion-referenced interpretations of standardized tests, educators must be sure that

question

actual performance of representative groups

answer

Which of the following best describes test norms?

question

greater than 7.5

answer

At the end of grade 5, Erik has a grade-equivalent score of 6.5 in reading. When he is at the end of grade 6 his score will most likely be

question

comparing performance on two tests

answer

Grade equivalent scores are least useful for

question

half the norm group had lower scores

answer

A percentile score of 50 on an achievement test indicates that

question

They have unequal units

answer

Which of the following is a disadvantage of percentile ranks?

question

Standard age score

answer

The z-score serves as the basis of which of the following?

question

They are based on the z-score

answer

Which of the following is true about T scores?

question

include only positive scores

answer

One advantage of T-scores over z-scores is that they

question

90.

answer

If a student ranks 5th in a class of 50, the percentile rank would be

question

T-score of 40

answer

In a normal distribution, which of the following scores equals a percentile rank of 16?

question

30 and 35

answer

The smallest number of percentile ranks fall between which of the following ranges of T-scores?

question

7.

answer

In a normal distribution a percentile rank of 84 would be the equivalent to a stanine of

question

score reliability

answer

The "score bands" used on the test profiles indicate which of the following?

question

Normal-curve equivalent = 80

answer

Other things being equal, which of the following represents the highest level of achievement?

question

T-score = 40

answer

In a normal distribution, which of the following represents the lowest level of achievement?

question

Stanines are based on a nine point scale.

answer

Which of the following statements about stanine scores is most accurate?

question

Agree

answer

Percentages and percentiles are interchangeable statistics. (Agree or Disagree)

question

False

answer

Norm relevancy should be left up to the test publisher. (True or False)

question

Agree

answer

It is legitimate for the test consumer to ask questions about the recency of test norms. (Agree or Disagree)

question

True

answer

The normal curve has the particular property of being symmetrical. (True or False)

question

False

answer

Percentile scores have equal intervals from one percentile rank to the next. (True or False)

question

False

answer

Stanine scores express scores in nine equal steps ranging from 1 (the highest) to 9 (the lowest). (True or False)

question

True

answer

NCE (Normal Curve Equivalent) scores can be averaged. (True or False)

question

True

answer

An NPR score of 67 means that 33% of the students who took the test earned higher scores.

question

False

answer

A student with an NPR (National Percentile Rank) of 50 is considered to be performing at the below average level. (True or False)

question

False

answer

It is accepted practice to compare a student's NPR scores earned on ELA, Math, Science, and Social Studies tests . (True or False)

question

True

answer

The Raw Score represents the number of questions that a student answered correctly. (True or False)

question

True

answer

A student with an NCE score of 50 is considered to be performing at the average level. (True or False)

question

True

answer

NPR (National Percentile Rank) CAN NOT be averaged. (True or False)

question

True

answer

A student with a stanine score of 6 is considered to be performing at the slightly above average range.

question

performance task

answer

The best method to assess a student's problem solving ability is through a simulation or through an "authentic" application of knowledge and skills that is commonly known as a(n) _____.

question

restrictive

answer

An essay question that focuses on the student's ability to provide specific information is called a(n) _____ essay.

question

extended

answer

An essay question that is meant to measure a student's ability to gather and integrate whatever information that is needed is called a(n) _____ essay.

question

validity

answer

The manner in which an achievement test's scores are interpreted and used impacts its _____.

question

effectiveness

answer

Pre- and Post-test results are commonly used in Louisiana as a measure of teacher _____ in the classroom.

question

sample

answer

A final examination that measures a student's ability to correctly spell 10 words out of the 800 words that were taught during the school year is NOT considered to provide an adequate measure of a student's spelling ability because of the small _____ size.

question

homogeneous

answer

One of the key characteristics of a matching test is that the stems and choices must be _____.

question

norm

answer

Describing the level of an individual's performance compared to that of a group represents a(n) _____ referenced interpretation.

question

criterion

answer

Describing the level of an individual's performance against a set of standards represents a(n) _____ referenced interpretation.

question

analytic

answer

A rubric that rates a student's performance using a range of descriptors that indicate/describe various levels of performance is known as a(n) _____ rubric.

question

norm-referenced test scores

answer

The NCE score is used in reporting _____.

question

70% of the students who took the test received a core that is equal to or less than the student in question.

answer

A student whose percentile rank is 70 suggest that _____.

question

indicate a student's level of mastery of content standards.

answer

A criterion-referenced test produces data that _____.

question

scoring

answer

A major problem in using essay questions to evaluate learning is the difficulty of _____.

question

constructing

answer

A major problem in using interpretive exercises to evaluate learning is the difficulty of _____.

question

true/false

answer

The type of test question that is most susceptible to guessing is _____.

question

how the scores are interpreted

answer

One measure of test validity involves _____.

question

pre-test and post-test

answer

What is the process that can be used to measure a teacher's effectiveness?

question

His percentage correct score is 91.

answer

Brent earned a score of 91 on a 100-item achievement test. Which of the following interpretations is MOST justified?

question

emphasis placed on the topic.

answer

Regarding teaching time-on-task, the distribution of items and tasks in a table of specifications should reflect the relative _____.

question

NCE

answer

This score is a norm-referenced score that has been adjusted so that it can be used in mathematical calculations.

question

Standard Score

answer

This score is produced from a single equal-interval scale of scores from kindergarten through grade 12.

question

NS

answer

This is the abbreviation for a stanine score.

question

NPR

answer

This score is based on the performance of a normed group of students.

question

%C

answer

This score is calculated by dividing the total number of correct responses by the total number of questions and then by multiplying the answer by 100.

question

Informal Assessment

answer

Measures student progress while informing the teacher and the learner of the extent that the presented course material is being learned and where no grades are recorded.

question

Formative Assessment

answer

Measures the extent that a student is making adequate progress during the presentation of course content over a period of several days.

question

Authentic Assessment

answer

Measures a student's ability to apply acquired knowledge and skills to a 'real life' simulation.

question

Summative Assessment

answer

Measures the extent that a student has acquired knowledge and skills after having completed a course.

question

Formal Assessment

answer

Measures student progress and involves the recording of a student's grades.

AP Statistics
Elementary Statistics
Grade Point Average
Probability And Statistics
Statistics

UCLA Stats 13 Quiz Questions Spring 2015 – Flashcards 84 terms
Thomas Owen

84 terms
Preview

UCLA Stats 13 Quiz Questions Spring 2015 – Flashcards

question

Select the appropriate word to identify whether the measurement represents a categorical variable or a quantitative variable: The average number of minutes a person watches television each day.

answer

Quantitative

question

Select the appropriate word to identify whether the measurement represents a categorical variable or a quantitative variable: The name brand of the pair of pants a person is wearing.

answer

Categorical

question

Is a person's favorite ice cream flavor (chocolate, vanilla, etc.) a categorical or quantitative variable?

answer

Categorical

question

In a large, national study, researchers asked seniors how many alcoholic beverages they had drank in the previous week. The distribution of number of drinks was strongly right-skewed. From this we can conclude that

answer

Most people in the sample had fewer than the average number of drinks.

question

A set of data is put into numerical order and a statistic is calculated that divides the data set into two equal parts. Which of the following statistics was computed?

answer

Median

question

A recent housing survey was conducted to determine the price of a typical home in Glendale, CA. Glendale is mostly middle-class, with one very expensive suburb. The mean price of a house was roughly $650,000. Which of the following statements is most likely to be true?

answer

Most houses in Glendale cost less than $650,000.

question

At a hospital they have collected data on the weight (in pounds) and ethnic background (African American, Asian American, Latino, White, and Others) of newborns. What is the best answer?

answer

There is one numerical and one categorical variable.

question

On the planet Tatooine where the annual famous podrace is held, there is an extensive database of race results going back a couple of decades. Among the variables are the order in which the racers finished (1st, 2nd, 3rd, ...), and their species (Human, Tusken Raider, Ewok, Wookiee, ...). What is the best answer?

answer

There is one ordinal variable and one categorical variable

question

Given a categorical variable with sufficient data, should we use a box plot to display our variable?

answer

FALSE

question

A random sample of dates taken from headstones at a cemetery in Pleasanton, California, showed an average lifespan of 70 years with a standard deviation of 20 years. Assuming the distribution is unimodal, which of the following is most likely a good description of the distribution? (consider the context in this question)

answer

The distribution is most likely skewed to the left.

question

Suppose that we create a new data set by doubling the highest value in a large data set of positive values. What statement is FALSE about the new data set?

answer

The median and interquartile range both increase

question

As part of an experiment in perception, 160 UCLA psych students completed a task on identifying similar objects. On average, the students spent 8.25 minutes with standard deviation of 2.4 minutes. However, the minimum time was 2.3 minutes and one students worked for almost 60 minutes. What is the best description of the histogram of times that students spent on this task?

answer

The histogram of times could be right skewed, and in the case of any outliers, it is likely that they will be larger than the mean.

question

Jim works in the admission office of a major state university in the east coast. He reports that of the 37000 undergraduates who attend this unversity, 47% are male. He then sends an email to every 10th senior and asks them if they plan to go to graduate school and he finds the percentage to be 23%.

answer

47% is a prameter and 23% is a statistic

question

Based on past experience, a bank believes that 4% of the people who receive loans will not make payments on time. The bank has recently approved 300 loans. What is the probability that over 6% of these clients will not make timely payments? (You May use the Java Applet to get the answer)

answer

between 0.038 and 0.055

question

Shelly is going to flip a coin 50 times and record the proportion of heads. Her friend Sidney is going to flip a coin 20 times and record the proportion of heads. Which person is more likely to get 20% or fewer heads?

answer

Sidney is more likely to get 20% or fewer heads since the smaller the sample size, the greater the variability in results.

question

A set of scores from a vocabulary test given to a large group of international students can be summarized with this five-number summary: {20,35,45,50,60} Determine which of the following statements about the distribution CANNOT be justified.

answer

There are more scores from 35 to 45 than scores from 45 to 50.

question

When a test of significance for the null hypothesis, Ho against the alternative, Ha, the p_value is:

answer

The probability of observing a value of the test statistic at least as extreme as that observed in the sample if Ho is true.

question

Records at a large university (not UCLA, of course) indicate that 20% of all freshmen are placed on academic probation at the end of the first semester. A random sample of 100 freshmen found that 25% of them were placed on probation. The results of the sample: (Note: You May use the Java Applet to get the answer)

answer

are not surprising since the standard deviation of the sampling distribution is 4%.

question

In a large statistics class, the professor has each student toss a coin 12 times and calculate the proportion of his or her tosses that were tails. The students then report their results, and the professor plots a histogram of these several proportions. Should a Normal model be used to represent the sampling distribution of the proportion of tails?

answer

A Normal model should not be used because the sample size is not large enough to satisfy the success/failure condition. For this sample size, np=6< 10

question

For a class project, every student in a statistics class with 90 students takes a random sample of 200 cars parked at UCLA and records the proportion of clean-air vehicles. (Assume that there are well over 2000 cars parked at UCLA on any given day.) Prior evidence collected by the university suggests that the population proportion is about 10%. Imagine looking at the list of 90 sample proportions. Which of the following is true?

answer

The distribution of sample proportions is well approximated by the Normal model, since the sample size of 200 cars is large enough.

question

According to the Pew Foundation, in a random sample of 1,044 Americans, only 36% of those sampled thought that global warming is due to human activity (down from 47% last year.) Identify the population, parameter, and statistic.

answer

The population is all Americans, the parameter is the percent who think global warming is due to human activity, and the statistic is 36%.

question

In Japan there is an annual turkey dog eating contest. The number of turkey dogs that contestants eat are normally distributed with a mean of 36 turkey dogs and a standard deviation of 6 turkey dogs. A contestant eats 27 turkey dogs. What is his z-score?

answer

-1.5

question

A histogram of a sample of data shows that the distribution is right-skewed. If the median of the sample is converted to standard units, which of the following is true?

answer

The z-score will be negative.

question

For the overall population, the IQ scores follow the normal distribution with mean equal to 100 and variance equal to 225. What is the best answer?

answer

If you pick a person at random, the chance that his IQ falls between 100 to 115 is more than the chance that his IQ falls between 60-85.

question

In standardized scores of achievement motivation that are normally distributed, the US group has a mean score of 35 with a standard deviation of 14. Higher scores correspond to more achievement motivation. Shamu scored in the top 20% of the test takers. What was her score?

answer

47

question

Among first-year students at a certain university, scores on the verbal SAT follow the normal curve. The average is around 500 and the standard deviation is about 100. Which of the following statements is correct?

answer

Andrew's score is the 60th percentile. So we know his score is 525.

question

The distribution of the number of hours that college students watch TV per week is unimodal with a mean of 3.7 and a standard deviation of 5. Is it appropriate to use the normal model to approximate the percentage of hours of TV watching within one standard deviation of the mean?

answer

No, it is not appropriate to use the normal model because it is impossible to watch negative hours of TV per week.

question

A consulting statistician reported the results from an experiment to the research psychologist, The report stated that on a particular phase of the experiment, a statistical result yielded a p_value = 0.24. Based on this p_value, which of the following conclusions should the psychologist make?

answer

The test was not statistically significant because, if the null hypothesis is true, one could expect to get a test statistic at least as extreme as our observation about 24% of the time.

question

Fluorescent light bulbs have lifetimes that follow a normal distribution, with an average life of 1,685 days and a standard deviation of 1,356 hours. In the production process the manufacturer draws random samples of 197 lightbulbs and determines the mean lifetime of the sample. What is the standard deviation of this sample mean?

answer

96.611

question

A researcher is examining the impact of a new method of teaching Farsi. She concludes that the new method is significantly better than the old method, based on a test with alpha = 0.05.

answer

She could have made the same decision at alpha = 0.10.

question

Which best describes a sampling distribution model of a statistic?

answer

It is a distribution of all the statistics calculated from all possible samples of the same size.

question

It is believed that 30% of the people in Washington state want cell phone use banned in cafes. The CEO of a major coffehouse chain in Seattle wonders whether the opinion of the people who go to her cafes is different from the overall population. She hires a polling agency to investigate this issue. In a random sample of 1450 individuals, 474 people have the same opinion as the overall population. What is the p-value?

answer

0.01271

question

A psychological test was performed on a group of 100 people using lottery tickets. Every participant was given a lottery ticket, and told that the prize was a free trip to the Bahamas. They were also told that one person had the winning ticket, but he or she didn't know that they had it. The participants were allowed to either exchange their ticket for another person's, or they could keep their original ticket. It had been assumed that 50 percent of the population would exchange their ticket for another one, but 72 of the 100 participants chose to do so. What are the null and alternative hypotheses, and which distribution should you use to test these hypotheses?

answer

H0: p = 0.50, Ha: p # 0.50, distribution = normal

question

A researcher is wondering whether a certain medication helps to lower blood pressure. 200 patients with high blood pressure volunteer to participate in the program. They take the medication for six months and record their blood pressure before and after taking the medication. The researcher does the relevant calculations and finds the Z value to be 1.2

answer

The p-value is 0.115 and the medication did not help to lower the blood pressure.

question

The Federalist Papers are a collection of essays written anonymously by some of the Founding Fathers after the American Revolution to try and convince the 13 states to form a federal government. Although we know who the authors are, we aren't sure who wrote which essay. Essay 28 may have been written by Alexander Hamilton or by James Madison. A historian has noticed that in the essays known to be written by Hamilton that are also around 200 sentences long, the average number of sentences started with a preposition are 68. Around 200 sentences were analysed from Essay 28. The historian finds that about 70 sentences start with a preposition, with a standard deviation of 14 sentences. He conducts a test of the hypothesis Ho:μ=68 against Ha:μ≠68. What is his p-value, and what conclusion can he draw from it?

answer

p.value = 0.043. He should reject the null hypothesis, and conclude that James Madison wrote the essay.

question

Food inspectors inspect samples of food products to see if they are safe. This can be thought of as a hypothesis test where H0: the food is safe, and HA: the food is not safe. If you are a consumer, which type of error would be the worst one for the inspector to make, a Type I or a Type II error?

answer

Type II

question

The Null and Alternative Hypotheses are statements about values of...

answer

The Population Parameters

question

Simulations used to find the distribution we use to find our p-value assume which hypothesis is true?

answer

The Null Hypothesis

question

Suppose you are testing the hypotheses H0=0.5 versus Ha>0.5. You get a sample proportion is 0.54 and find that your p-value is 0.08. Now suppose you redid your study with each of the following changes, will your new p-value be larger or smaller than 0.08 your first obtained? 1) You increase the sample size and still find a sample proportion of 0.54. Your new p-value will be... 2) Keeping the sample size the same, you take a new sample and find a sample proportion of 0.55. Your new p-value will be: 3). With your original sample, you decided to test a two-sided alternative instead of Ha: >0.5. Your new p-value will be:

answer

1) Smaller 2) Smaller 3) Larger

question

Suppose you want to determine if a majority of students at your school watched the Super Bowl. You take a random sample of 100 students and find that 54 watched the Super Bowl. You then run an appropriate test of significance. What is the parameter in this situation?

answer

The proportion of all the students at your school that watched the Super Bowl.

question

In the Super Bowl scenario from a previous question, suppose that after running the appropriate test you get a standardized statistic of 0.8. What does this standardized statistic mean?

answer

Your observed statistic of 0.54 is 0.8 standard deviations above the mean of the null distribution.

question

T or F: The Standard of Error(Standard Deviation of the Chance Model) will decrease as the sample size decreases.

answer

FALSE

question

The basic premise of hypothesis testing is to assume a status quo statement and examine sample information to assess the validity of the original statement. In order to no longer believe in the validity of the status quo statement, the sample statistic would need to be _______ to the population parameter

answer

unusual compared

question

Statistical software produces the following output while testing the mean height of a group of children being 45 inches tall. What is the best interpretation of the p-value if it is 0.757?

answer

A sample mean of this value or more extreme would occur 75.7% of the time by chance alone given a true null hypothesis.

question

T or F: The CLT states that the sample distribution model of the sample mean (and proportion) from a random sample is approximately Normal for any n, regardless of the distribution of the population, as long as the observations are independent.

answer

FALSE

question

One of the assumptions needed to use a z-distribution for statistical analysis is very difficult to obtain in practice, that is _____

answer

obtaining a value for the population standard deviation

question

Suppose two researchers wanted to determine if aspirin reduced the chance of a heart attack. Researcher 1 studied the medical records of 500 patients. For each patient, he recorded whether the person took aspirin every day and if the person had ever had a heart attack. Then he reported the percentage of heart attacks for the patients who took aspirin every day and for those who did not take aspirin every day. Researcher 2 also studied 500 people. He randomly assigned half of the patients to take aspirin every day and the other half to take a placebo everyday. After a certain length of time, he reported the percentage of heart attacks for the patients who took aspirin every day and for those who did not take aspirin every day. Suppose that both researchers found that there is a statistically significant difference in the heart attack rates for the aspirin users and the non-aspirin users and that aspirin users had a lower rate of heart attacks. Can both researchers conclude that aspirin caused the reduction?

answer

No, only researcher 2 can conclude this

question

Scientists are interested in the effects of the sun on growth of moss on trees above the Arctic Circle. 25 years of data is collected and then analyzed. The study shows that the moss grows the most in the years where there is a moderate amount of sun during the summer, and the least in the years where the sun is mostly obscured by clouds during the summer. This is an example of an

answer

observational study from which we cannot draw causal conclusions

question

A psychologist is examining the effect of showing pictures on learning of words by seven-year-olds. The seven-year-olds are randomly assigned to two groups. The experimental group is shown the word along with the picture. The control group is shown only the word. At the end of the experiment, the subjects are given a test on the number of words they get right. This is an example of:

answer

A well-designed experiment

question

They are showing a new movie at a neighboring theatre. You are hired to ask a sample of 200 people whether they liked the movie or not. You should compute and report the percentage of the people who said "Yes". What kind of sampling method do you recommend?

answer

Systematic Random Sampling

question

A polling agency wants to find out if the proportion of people who vote for candidate X is higher than the proportion who will vote for candidate Y. What statistical method should he use to test this null?

answer

Two-sample test of the proportion

question

A teacher wants to examine the impact of using technology on teaching microbiology. He teaches two sections of Microbiology; one at eight and one at ten AM on MWF. He randomly assigns one of the classes to teaching with technology. The students in the the technology class get to know that they are part of an experiment and they try really hard to make the class a success. This is an example of

answer

Hawthore Effect

question

A study indicated that elderly people (age 70 and higher) who had pets lived longer and became less depressed than elderly people who did not have pets. The data came from the records of 700 elderly people who went to a local clinic for treatment. Based on pre-existing medical records, 400 had pets and 300 did not. Choose the best answer.

answer

This is an observational study because the data are obtained from the pre-exisiting medical records of the patients who refer to the local clinic.

question

Several researchers have theorized that humans have longer growth spurts when they live in areas that get more sunlight year-round than other areas. They collect data on the heights of teenaged boys from Equitorial Guinea and from Norway. They also collect data on the hours of sunlight per day for the years that the boys were growing. They conclude that sunlight does cause humans to grow taller.

answer

The researchers' conclusions are not correct because this is an observational study and you can't draw causal conclusions from observational studies

question

An examination of the medical records of more than 250,000 women in the 20-40 year age range indicated that those who were overweight had longer than average labor when their first child was born. The study concluded that above average weight causes women in the 20-40 year age range to have longer labor when delivering their first child.

answer

This conclusion is not correct because there are many other factors other than weight that could contribute to long labor.

question

We want to examine the effectiveness of three programs on the weight loss of men and women in the 40-50 year old age range. 150 men and 150 women participate in the study. Subjects are randomly assigned to the three programs. They spend 3-4 hours in the program per week and they continue the program for six months. Their weight is recorded before and after the program. Choose the best answer

answer

This is an experimental study because the subjects have been randomly assigned to different treatment groups

question

Suppose that you wanted to conduct a study and seek the opinion of UCLA undergraduates regarding the elimination of SAT from admission requirements to UCLA. For a large random sample of 600 undergraduate students, the 90% confidence interval is from 0.28 to 0.52. What is the best interpretation of this confidence interval?

answer

We are 90% confident that between 28% to 52% of the UCLA students endorse elimination of SAT from admission requirements

question

A doctor wants to find out if a new medication lowers the blood pressure. 30 patients who have volunteered to take the medication. He measures their blood pressure before taking the medication and six months after taking the medication. What statistical method do you recommend for testing the null hypothesis?

answer

This sample is dependent and in order to test the null he should use the paired- sample test of the mean.

question

A polling agency wants to find out if the proportion of people who vote for candidate X is higher than the proportion who will vote for candidate Y. What statistical method should he use to test this null?

answer

Two-sample test of the proportion

question

Armando works in a research institute and they have collected the following data on a random sample of 500 students, Gender GRE score before and after participation in a GRE prep course (GRE is a test you take for entering graduate school) Armando wants to answer questions the following questions: Question one: After taking the GRE preparation course, did women show more improvement on the GRE score or men? Question two: After the GRE preparation course, did more women get admitted to the graduate program or men? What statistical method should he use?

answer

He should use the two-sample test of the mean to answer question one and the two-sample test of proportion to answer question two

question

An article in a sociology journal reports a two-tailed p-value of 0.040 for a test of the null hypothesis that there in no difference between the percentage of men and women who endorse marriage outside one's own religion. If the authors had reported a 95% confidence interval in addition to the P value, which of the following would be true?

answer

Based on the P value given above males and females are not similar with respect to their opinions and the CI should not be expected to capture zero.

question

A researcher wants to compare all students at Kansas State University (population = 22,000) with all residents of the city of Springfield, IL (population = 22,000). He wants to estimate the average age of each population using two separate samples. He wants the same margin of error for each of his sample means. How would the size of the two samples compare?

answer

The KSU sample should be smaller than the Springfield sample.

question

A consulting statistician reported the results from an experiment to the research psychologist, The report stated that on a particular phase of the experiment, a statistical result yielded a p_value = 0.24. Based on this p_value, which of the following conclusions should the psychologist make?

answer

The test was not statistically significant because, if the null hypothesis is true, one could expect to get a test statistic at least as extreme as our observation about 24% of the time.

question

A researcher wants to find out if the proportion of citizens who endorse spending more money on HIV research is different in states one and two. For a random sample of 200 citizens from state one, 120 endorse spending more money on HIV research. For a random sample of 200 citizens from stat two, 140 endorse spending more money on HIV research. What is the underlying distribution for the above scenario and what is the standard deviation of this distribution?

answer

We are taking about the distribution of p^1 - p^2 and the standard deviation of this distribution is equal 0.0477.

question

138 students were taught mathematics through cooperative learning. They were pre-tested and post-tested on their knowledge of fractions and the following data was reported. They wanted to find out if on average the students showed any gain on knowledge of fractions. -Pre-test mean =39.6 -Post-test mean = 59.41 -r (correlation between pre and post data ) = 0.46 -95% CI = 15.8, 23.72

answer

The statistical method used was the paired-sample test of the mean and the null was rejected

question

An article in a sociology journal reports a two-tailed p-value of 0.040 for a test of the null hypothesis that there in no difference between the percentage of men and women who endorse marriage outside one's own religion. If the authors had reported a 95% confidence interval in addition to the P value, which of the following would be true?

answer

Based on the P value given above males and females are not similar with respect to their opinions and the CI should not be expected to capture zero.

question

For the one sample test of the mean If N = 19 For a two tailed test Given that we want 99% confidence, what are the values corresponding to t?

answer

The corresponding t values are +/- 2.878

question

Jordan is testing a hypothesis regarding the effect of having a part time job on the GPA of undergraduate students. For a random sample of 200 undergraduates who have part time jobs and 200 who do not, he finds the following confidence interval for the difference of GPA for students who have part time jobs and those who do not. He finds this confidence interval to be from minus 0.20 to plus 0.20 (-0.20 to +0.20). What is the best answer?

answer

He should fail to reject the null hypothesis and conclude that having a part time job in not related to the GPA of undergraduate students.

question

A doctor wants to find out if a new medication lowers the blood pressure. 30 patients who have volunteered to take the medication. He measures their blood pressure before taking the medication and six months after taking the medication. What statistical method do you recommend for testing the null hypothesis?

answer

This sample is dependent and in order to test the null he should use the paired- sample test of the mean.

question

Jay is testing a null hypothesis regarding the relationship of marital status (married and single) on GPA of graduate students who major in social science. For a random sample of 100 married and 100 single students he finds the following 95% CI for the difference in the GPA of married and single students is from minus 0.40 to plus 0.30 (-0.40 to + 0.30) What is the best answer?

answer

He should fail to reject the null and conclude that marital status has is not related GPA

question

The objective of a study is to find out whether meditation lowers stress level. Thirty six people volunteer to participate in the study. They meditated for one hour and their stress level was measured before and after meditation.

answer

Reject the null and conclude that meditation lowers the stress level.

question

A sociology professor wants to find out if there is a relationship between major and spending junior year abroad. Using the registrar's list she chooses a random sample of 200 non-science majors and 200 science majors and computes the proportion who spend the junior year abroad. What statistical method should this professor use to examine the relationship between major and spending junior year abroad?

answer

Two-sample test of percentage

question

A researcher wants to examine the effectiveness of a weight loss program. 100 people volunteer to participate in the study and he randomly assigns 50 of them to the new program which consists of yoga and weight training and 50 to weight training only. He collects the following data weight prior to program weigh after program calories consumed per day gender What is the best analysis to run?

answer

two sample test of the mean on the amount of weight loss for the control and experimental group

question

For this research situation, decide what statistical procedure would most likely be used to answer the research question posed. Assume all assumptions have been met for using the procedure. Is ethnicity related to political party affiliation (Republican, Democrat, Other)?

answer

Use a chi-squared test of association.

question

We are interested in seeing is support for a school bond issue differs by neighborhood in a city. What statistical method should we use to answer our question?

answer

Use a chi-squared test of association.

question

A researcher uses a chi-square test to determine if there is a relationship between 2 categorical variables. Which of the following p-values indicates the strongest evidence of such a relationship?

answer

.002

question

A study claims that there is a relationship between gender (male/female) and the type of magazine (fashion and sport) that people look through when they are on the thread mill. What type of chart would you use to show whether such a relationship exists or not.

answer

Segmented Bar Charts

question

A researcher has collected the following information on a random sample of 200 adults in the 40-50 age range: Weight in pounds Heart beats per minute Smoker or non-smoker Single or married He wants to examine the relationship between: 1) heart beat per minute and weight, and 2) smoking and marital status. What is the best answer?

answer

He should draw a scatter plot of heart beat and weight, and a segmented bar chart of smoking and marital status.

question

Which of the following is the correct notation for a χ2 -critical value for a sample size of 20 and an α=0.10 for a greater than alternative hypothesis?

answer

χ2 (19,0.10)

question

Find the value of χ2 (10,0.05)

answer

18.3

question

Which of the following situations will add the largest component to a chi-Square statistic?

answer

an expected value of 10 and an observed value of 7

question

In order to test the fairness of a random number generator, a set of 300 numbers is chosen from the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}. A tally table for each of the outcomes is prepared. What would the expected value for the occurrence of a seven be?

answer

30

question

Forty subjects are asked about their preferred method to obtain the national news daily. They respond in five categories; national newspaper, local newspaper, internet, nightly TV news, or from another individual. How many degrees of freedom does the hypothesis test to determine if there is a statistical difference in preference have?

answer

4

question

Forty subjects are asked about their preferred method to obtain the national news daily.They respond in five categories; national newspaper, local newspaper, internet, nightly TV news, or from another individual.If the observed values are all very close to the expected values, the Chi-Square statistic should be ______.

answer

Close to Zero

AP Statistics
Statistics

Sociology Chapter 12- Education and Society – Flashcards 54 terms
Sabrina Peterson

54 terms
Preview

Sociology Chapter 12- Education and Society – Flashcards

question

What percentage of students who complete high school go on to enroll in a college program? a. 70 b. 65 c. 95 d. 46

answer

70

question

Education is increasingly important for job seekers due primarily to which of the following factors? a. High unemployment rates b. Transition to a post-industrial economy c. Rising cost of living d. Low rates of pay

answer

Transition to a post- industrial economy

question

What percentage of students who enroll in college complete a degree? a. 65 b. 30 c. 46 d. 70

answer

46

question

Which of the following reasons illustrates a micro-level explanation for why education is important? a. The U.S. economy needs an educated workforce. b. States invest billions of dollars to cover education costs for students who never finish. c. Higher numbers of dropouts makes the United States less competitive globally. d. Median weekly earnings are higher for those with a college education.

answer

Median weekly earnings are higher for those with a college education

question

The transmission of society's norms, values, and knowledge base by means of direct instruction is referred to as: a. Socialization b. Acculturation c. Education d. Internship training

answer

Education

question

School segregation based on residential patterns or student choice, despite the legal segregation being banned, is referred to as: a. De jure segregation b. Residual segregation c. De facto segregation d. Effectual segregation

answer

De facto segregation

question

Schools were originally established in the United States for which of the following purposes? a. Training workers in a particular craft b. Educating children to read biblical literature c. Teaching the public to read and write d. Teaching people workplace habits and skills

answer

Educating children to read biblical literature

question

A society in which access to desirable jobs and social status depends on the possession of a certificate or diploma is referred to as: a. Credential society b. Globalized society c. Post-industrial society d. Western society

answer

Credential society

question

Which of the following is associated with the highest levels of income? a. Doctoral degree (PhD) b. Master's degree c. Professional degree d. Associate's degree

answer

Professional degree

question

Which of the following is an example of the sociological term "moral education"? a. Fifth graders learning about laws and rights. b. Kindergartners learning how to behave in class. c. Children learning to read biblical literature. d. High school students learning about inequality.

answer

Kindergartners learning hoe to behave in class

question

Which of the following is true of the relationship between race and education? a. Blacks and Latinos are less likely than Whites to complete their bachelor's degree within six years of starting b. Latino and Black students are less likely to be in segregated schools today than in earlier decades c. Even though schools are racially segregated, they are equally funded d. Mandated school busing was widely accepted as an integration policy

answer

Blacks and latinos are less likley than whites to complete their bachelors degree within six years of starting

question

On which of the following points do conflict and functionalist theorists agree? a. A high school degree is necessary for equal opportunity. b. Education channels individuals into positions for which they are best suited. c. Education trains people in the dominant norms and values of society. d. Education reproduces social inequality.

answer

Education trains people in the dominant norms and values of society

question

On which of the following points do conflict and functionalist theorists agree? a. A high school degree is necessary for equal opportunity. b. Education channels individuals into positions for which they are best suited. c. Education trains people in the dominant norms and values of society. d. Education reproduces social inequality.

answer

Education trains people in the dominant norms and values of society

question

According to conflict theorists, the "hidden curriculum" is a latent function of education that does which of the following? a. Teaches members of the working class important skills for advancement b. Socializes members of the working class to accept their class positions c. Exposes children of all classes to equal opportunities d. Places less talented students into lower level classes

answer

Socializes members of the working class to except their class positions

question

Which of the following is an example of a symbolic interactionist approach to studying education issues? a. Analyzing data about the relationship between education status and income b. Observing how certain students perform in class after being labeled as "exceptional" c. Studying patterns of racial segregation in public education d. Studying the reproduction of inequality in mass education

answer

Observing a certain students perform in class after being labeled as "exceptional"

question

Which of the following is true of the relationship between education and income? a. College graduates today are out-earning earlier graduates in regard to entry-level wages after graduation b. About 75% of new graduates have an employment offer at the time of graduation c. Wages in the United States have kept pace with inflation d. College graduates out-earn their peers with only a high school education

answer

College graduates out earn their peers with only a high school education

question

Of the four literacy levels determined by the National Assessment of Adult Literacy (Below Basic, Basic, Intermediate, and Proficient), what percentage of Americans have proficient literacy? a. 92 b. 75 c. 27 d. 13

answer

13

question

The Supreme Court case that upheld the states' right to segregate public accommodations is known as: a. Brown versus Board of Education of Topeka b. Plessy versus Ferguson c. Jim Crow laws d. "Separate but equal"

answer

Plessy versus Ferguson

question

What method of achieving school integration is known for worsening racial conflict in South Boston? a. The implementation of educational vouchers b. Forced desegregation c. Revision of school funding formulas d. Mandated school busing

answer

Mandated school busing

question

College graduation rates are higher at private colleges than at public institutions a. True b. False

answer

True

question

Which of the following racial minority groups is least likely to attend segregated schools? a. Asian Americans b. Latinos c. African Americans d. American Indians

answer

Asian americans

question

Which of the following racial minority groups is most likely to attend segregated schools? a. Asian Americans b. Latinos c. African Americans d. American Indians

answer

American Indians

question

Only about 25% of students today fit the model of full-time, on-campus students supported largely by their parents. a. True b. False

answer

True

question

Although access to books at home and early reading experiences are related with higher performance at the early grade level, the literacy gap is easily closed within the first two or three years of schooling. a. True b. False

answer

False

question

Which of the following racial groups is most likely to experience heavy educational debt (defined here as $30,500 or more at graduation)? a. Asian Americans b. Latinos c. African Americans d. Whites

answer

African Americans

question

Which of the following is the most common reason cited for why students dropped out of college? a. They needed to leave school to support a family. b. They preferred working and earning money. c. They could not afford to stay enrolled. d. They were no longer interested in the subject of study.

answer

They could not afford to stay enrolled

question

During the 2008 global economic recession, which group was most affected by unemployment of the 34 OECD states? a. Adults without a high school education b. Adults without post-high school education c. Adults with a four-year college degree d. Adults with a PhD

answer

Adults with post- high school education

question

Which of the following is the number one destination for U.S. students who travel abroad? a. United Kingdom b. China c. Greece d. Indonesia

answer

United Kingdom

question

Of the four literacy levels determined by the National Assessment of Adult Literacy (Below Basic, Basic, Intermediate, and Proficient), what percentage of Americans fell Below Basic? a. 5 b. 14 c. 32 d. 1

answer

14

question

The ability to read and write at a level sufficient to fulfill everyday practical needs is referred to as: a. Basic literacy b. Functional literacy c. Verbal proficiency d. Verbal literacy

answer

Basic literacy

question

According to the National Center on Education Statistics (NCES), in 2009, about what percentage of U.S. students dropped out of high school? a. 5 b. 10 c. 32 d. 8

answer

8

question

Universal education systems provided by the government and funded by tax revenues rather than student fees are referred to as: a. Public education b. Charter education c. Parochial education d. Municipal education

answer

Public education

question

Universal public education emerged out of demands made by labor unions in the 19th century. a. True b. False

answer

True

question

Following the abolition of slavery, and before Jim Crow law took effect, Black and White children were educated in the same school systems. a. True b. False

answer

True

question

Fifty years after the Civil Rights Movement, racial school segregation is no longer a pattern in U.S. society. a. True b. False

answer

False

question

A longer school day has been shown to correlate with academic gains. a. True b. False

answer

True

question

The traditional school year with a summer break was designed to accommodate the needs of families sustained by agriculture. a. True b. False

answer

True

question

While there is a measurable relationship between higher levels of education and higher levels of income, it is not significant. a. True b. False

answer

False

question

Those with more education are more likely to participate in the paid labor force and less likely to face unemployment. a. True b. False

answer

True

question

Although the manufacturing sector has declined significantly, manufacturing jobs are just as likely to be unionized, provide long-term job security, and pay a living wage as they were in the past. a. True b. False

answer

False

question

Prior to _____, middle- and upper-class children attended private schools to be trained for business and education, while lower class children attended public schools to learn skills and obedience for factory work and farming. a. universal public education b. education reform c. desegregation d. mass education

answer

Universal public education

question

According to contemporary functionalist perspectives, the transmission of knowledge and skills is a _____ function of education, while the propagation of norms and values is a _____ function. a. manifest, latent b. latent, manifest c. practical, moral d. practical, intended

answer

Manifest, latent

question

_____ refers to the education of racial minorities in schools that are geographically, economically, and/or socially separated from those attended by the racial majority. a. Educational discrimination b. Racial tracking c. School segregation d. Racial inequality

answer

School segregation

question

In the South, school segregation was a result of _____ ; in the North, it was a result of _____. a. Jim Crow laws, residential segregation b. Jim Crow laws, income differences c. income differences, residential segregation d. residential segregation, income differences

answer

Jim crow laws, income differences

question

The Supreme Court case reversed _____ in 1954 when it ruled that segregating public schools was unconstitutional in the case called _____. a. Brown versus Board of Education of Topeka, Plessy versus Ferguson b. separate but equal, Plessy versus Ferguson c. Plessy versus Ferguson, Brown versus Board of Education of Topeka d. school segregation, Brown versus Board of Education of Topeka

answer

Plessy versus Ferguson, Brown versus Board of Education of Topeka

question

The current U.S. labor market is mostly made up of _____ and _____. a. advanced professional occupations that require higher education; part-time, low-pay, low-benefit service jobs b. advanced professional occupations that require higher education; manufacturing jobs that require a high school diploma c. Manufacturing jobs that require a high school diploma; part-time, low-pay, low-benefit service jobs d. white-collar occupations that require education; service jobs for undocumented

answer

advanced professional occupations that require higher education; part-time, low-pay, low-benefit service jobs

question

U.S. students attend on average about 180 school days per year, while students in Italy attend ____ days per year and students in Korea attend ____ days per year. a. 200, 220 b. 175, 200 c. 200, 180 d. 220, 250

answer

200,220

question

According to the Organization for Economic Cooperation and Development (2011), the United States ranks ____ in the percentage of young adults with a college degree. a. 1st b. 5th c. 16th d. 26th

answer

16th

question

Which of the following is NOT characteristic of mass education? a. The belief that education is a birthright of all citizens. b. The extension of formal schooling to wide segments of the population c. The transition from an apprentice model to direct instruction in schools d. The principle means of training workers and citizens

answer

The transition from an apprentice model to direct instruction in schools

question

Which of the following is NOT a latent function of mass public education? a. Keeping children occupied during the day while their parents work b. Socializing children with their peers c. Teaching public values d. Teaching important workplace habits and skills

answer

Teaching important workplace habits and skills

question

Poverty among children is NOT linked to which of the following factors? a. Economic disadvantage b. Language-impoverished environments c. Limited access to books in the home d. Individual learning challenges, such as dyslexia

answer

Individual learning challenges, such as dyslexia

question

Which of the following is NOT a factor contributing to educational inequalities between racial groups? a. School funding formulas based on property taxes b. Residential segregation c. Income inequality d. Affirmative action policies

answer

Affirmative action policies

question

Which of the following is NOT considered a service sector occupation? a. Medical assistant b. Cable television sales rep c. Sewing machine operator in a garment factory d. Daytime garden laborer

answer

Sewing machine operator in a garment factory

question

Which of the following is NOT a reason schools should consider summertime education? a. Some research suggests that children may lose up to two months of acquired skills over the course of the summer. b. Schools would receive more revenue. c. Middle- and upper-income students are often sent to attend enriching summer camps, which widens the educational gap for low-income students. d. Working parents have a difficult time finding childcare in the summer.

answer

Schools would receive more revenue

AP Statistics
Authoritative Parenting Style
Different From The Others
Goals
Grade Point Average
Hypothesis Testing
Present Tense
Public High School
School Psychology
Statistics

3rd Millennium Classrooms:: Alcohol-Wise (Pre-test) – Flashcards 45 terms
Ewan Tanner

45 terms
Preview

3rd Millennium Classrooms:: Alcohol-Wise (Pre-test) – Flashcards

question

What percentage of first-year students fail to enroll their second year?

answer

33%

question

Select the statement that is true about alcohol tolerance.

answer

If you reach a BAC level beyond a normal social drinking range and do not feel some of the effects of lower BACs, you have a higher tolerance for alcohol.

question

Which of the following statements is true about college students and drinking?

answer

On average, two out of three college students drink two or fewer alcoholic beverages a week.

question

Which of the following statements is true about college drinking?

answer

Many college students have exaggerated views about the quantity and frequency of drinking among their peers.

question

Alcohol-related accidents and violence are the leading cause of death for Amercians under the age of 35. If you drive with a BAC in the .10 to .14 range, your chances of being killed in a single-vehicle crash are:

answer

48 times more likely

question

Which of the following beverages has the highest amount of alcohol?

answer

They all have the same amount

question

How does drinking on an empty stomach affect peak blood alcohol concentration?

answer

Peak BAC can be three times as great for a person who drinks on an empty stomach

question

Which of the following beverages has the highest concentration of alcohol?

answer

12 ounce beer 5 ounce glass of wine 1.5 ounce shot of 80 Proof whiskey

question

The unit used to express the amount of alcohol that is circulating in your blood stream is called Blood Alcohol Concentration (BAC) and is determined by the following factors. Select all that apply.

answer

Gender (male or female) Type of alcohol you drink (beer, wine, or whiskey) Amount of alcohol consumed Body weight Time it takes to consume it

question

A person has 3 beers in an hour. How long does it normally take to process and eliminate this alcohol from the system?

answer

3 hours

question

At what level of drinking do risk factors increase for health, academic, and social problems?

answer

5 or more drinks in a sitting for males, 4 drinks for females

question

Select the following statements that are true about BAC. Select all that apply.

answer

- BAC acts as a thermometer. A higher BAC results in a higher level of intoxication - Women generally develop higher blood alcohol levels than men after consuming similar amounts of alcohol. - Drinking on an empty stomach may result in a higher BAC level.

question

Select two party tips that are indicators of moderate drinking behavior. Select all that apply.

answer

- Eat a meal before you drink - Choose the least intoxicated person in your group to be the designated driver - Space and pace your drinking to about one drink per hour

question

What consequences of heavy drinking do men and women experience differently? Select all that apply.

answer

- Women are more likely to be impaired if they drink comparable amounts of alcohol - Women are at greater risk for blackouts - Women are more likely than men to experience unwanted sexual advances and depression

question

What are some things you can do to reduce the secondary effects of a neighbor or roommate's heavy drinking? Select all that apply.

answer

- Find a quiet place to study - Walk away from confrontation - Stay away from unsafe parties and events - Be a good neighbor

question

Alcohol first affects the area of the brain that controls....

answer

Breathing Emotions Judgment

question

Rapid consumption of multiple drinks or Jell-O shots puts a high concentration of alcohol in the body in a short time. Why is this dangerous?

answer

Higher concentrations of alcohol suppress breathing. This can cause alcohol poisoning and even death.

question

What are some safer ways to get home from a party if you've been drinking? Select all that apply.

answer

Arrange for a designated driver before you drink Call a taxi, sober friend or family member

question

What should you do if a person passes out at a party? Select all that apply.

answer

- Attempt to wake them up - Let them sleep it off - Call 911 if they don't respond - Don't leave them alone - Try to get them in a cold shower

question

Which of the following statements is true about the effects of combining alcohol and caffeine? Select all that apply. (Select all that apply)

answer

Caffeine masks the depressant effects of alcohol, which makes a person feel less intoxicated than they really are. The caffeine and alcohol mixture causes dehydration. There is no negative effect of combining alcohol and caffeine. Once the caffeine wears off, the full depressant effects of the alcohol hit. This can lead to a nasty hangover.

question

How long does it take the body to metabolize a given amount of alcohol?

answer

About one drink per hour

question

Craig attends a party and has 4 mixed drinks. How long should Craig wait before driving home?

answer

We don't know. (mix drinks vary)

question

What often occurs when a person's blood alcohol level exceeds a .06% BAC?

answer

Increased drinking above a .06 BAC results in fatigue, slower breathing, reduced coordination, drowsiness, and a general 'down' feeling.

question

What is an alcohol-induced BLACKOUT?

answer

An alcohol-induced blackout is typically caused by gulping too many drinks, too quickly. The intoxicated person cannot recall key details of events or even entire events.

question

Increase on my BAC

answer

- Recent loss of blood - Certain emotional states, or a menstrual cycle phases - Being on a diet or under normal weight - Using alcohol in combination with other drugs - Drinking on an empty stomach

question

Decrease on my BAC

answer

- Drinking after a full meal - Processing alcohol more rapidly than most people - Menstrual cycle phases

question

Approximately how many calories are in one standard alcoholic beverage?

answer

100-150 calories

question

What are the associations between excessive drinking and academic performance? Select all that apply.

answer

- Heavy drinking contributes to some sleep disorders which can lead to lower grades. - High-risk drinkers are far more likely than moderate drinkers to miss class, fall behind on schoolwork, and perform poorly on a test or project. - Frequent, high-risk drinking makes it more difficult to remember what was just learned.

question

You're at a party, and an intoxicated person goes to sleep or loses consciousness. What's the first thing you should do?

answer

Immediately attempt to wake this person up, and get him or her to respond.

question

What do campus social norms tell us? (Select all that apply)

answer

- Many college students overestimate the amount of heavy drinking on their campus. - Credible surveys demonstrate much lower drinking rates on campus than students assume. - There may be some social pressures to drink, but it's not as evident as in previous years.

question

Alcohol can interfere with sleep patterns, muscle recovery and healing.

answer

true

question

Which of the following are indicators that a person has a serious problem with alcohol? Select all that apply.

answer

- Hiding liquor or lying about drinking - Blackouts due to drinking - Increased absenteeism or lateness to class or job

question

Which of the following was not mentioned as a factor in hangovers?

answer

Caffeine

question

More likely to become more intoxicated when drinking the same amount of alcohol

answer

Women

question

More likely to be depressed

answer

Women

question

More likely to get into fights

answer

Men

question

More likely to have academic problems

answer

Both men and women

question

Before you drink, what are some safer ways to get home? Select all that apply.

answer

- Arrange for a designated driver before you drink. - Call a taxi. - Call a sober friend or family member and ask for a ride.

question

Nearly 47% of people who began drinking before age 14 were alcohol dependent at some point in their lifetime.

answer

true

question

Which of the following statements is true about the effects of combining alcohol and caffeine? (Select all that apply)

answer

- Caffeine masks the depressant effects of alcohol, which makes a person feel less intoxicated than they really are. - The caffeine and alcohol mixture causes dehydration. - Once the caffeine wears off, the full depressant effects of the alcohol hit. This can lead to a nasty hangover.

question

How do many members of the campus community (including faculty and staff) view high-risk drinking at their college?

answer

The campus community tends to overestimate estimate the number of students who drink heavily and use other drugs.

question

When should you definitely abstain from using alcohol? Select all that apply.

answer

- If you've developed a dependency on alcohol - If you're pregnant - If you plan on operating a motor vehicle

question

How long does it normally take to process one 12-ounce beer from your system?

answer

question

Which of the following statements is true about BAC?

answer

question

What do campus social norms tell us? Select all that apply.

answer

Elementary Statistics
Statistics

Winter statistics 1.1 – Flashcards 64 terms
Sean Mitchell

64 terms
Preview

Winter statistics 1.1 – Flashcards

question

Statistics

answer

is the science of collecting, organizing, summarizing, and analyzing information to draw or answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.

question

data

answer

a fact or proposition used to draw a conclusion or make a decision. it describe characteristics of an individual

question

Data can be

answer

numerical, as in height, or nonnumerical, as in gender

question

Anecdotal means

answer

that the information being conveyed is based on casual observation, not scientific research

question

population

answer

The entire group of individuals to be studied

question

individual

answer

is a person or object that is a member of the population being studied.

question

sample

answer

is a subset of the population that is being studied.

question

descriptive statistic

answer

it describes the results of the sample without making any general conclusions about the population consist of organizing and summarizing data. describe data through numerical summaries, tables, and graphs.

question

statistic

answer

is a numerical summary of a sample

question

This is an example of what "Suppose 39 of the 50 students stated that they would return the money to theowner.We could present this result by saying the percent of students in the survey that stated they would return the money to the owner is 78%"

answer

Descriptive statistic

question

Inferential statistics

answer

uses methods that take a result from a sample, extend it to the population, and measure the reliability of the result.

question

If we extend the results of our sample to the population and say that the proportion of all students at the school who would return the money is 78%, we are performing

answer

Inferential statistics

question

parameter

answer

is a numerical summary of a population.

question

Suppose the percentage of all students on your campus that own a car is 48.2%. Is this a statistic or parameter?

answer

This value represents a parameter because it is a numerical summary of a population.

question

Suppose a sample of 100 students is obtained, and from this sample we find that 46% own a car. is this a statistic or parameter ?

answer

This value represents a statistic because it is a numerical summary of a sample.

question

convenience samples

answer

Many nonscientific studies are based on Internet surveys or phone-in polls. The results of any study performed using this type of sampling method are not reliable.

question

The Process of Statistics

answer

1. Identify the research objective, 2. Collect the data needed to answer the question(s) posed in (1). 3. Describe the data. 4. Perform inference

question

1. Identify the research objective.

answer

A researcher must determine the question(s) he or she wants answered.The question(s) must be detailed so that it identifies the population that is to be studied.

question

2. Collect the data needed to answer the question(s)

answer

Gaining access to an entire population is often difficult and expensive. When conducting research, we typically look at a sample. The collection of data step is vital to the statistical process, because if the data are not collected correctly, the conclusions drawn are meaningless. Do not overlook the importance of appropriate data-collection processes.

question

3. Describe the data

answer

Obtaining descriptive statistics allows the researcher to obtain an overview of the data and can provide insight as to the type of statistical methods the researcher should use

question

4. Perform inference

answer

Apply the appropriate techniques to extend the results obtained from the sample to the population and report a level of reliability of the results.

question

Variables

answer

are the characteristics of the individuals within the population.

question

Qualitative

answer

categorical, variables allow for classification of individuals based on some attribute or characteristic.

question

Quantitative variables

answer

provide numerical measures of individuals. Arithmetic operations such as addition and subtraction can be performed on the values of a quantitative variable and will provide meaningful results.

question

approach

answer

or a way to look at and organize a problem so that it can be solved

question

Distinguishing between Qualitative and Quantitative Variables (a) Gender

answer

(a) Gender is a qualitative variable because it allows a researcher to categorize the individual as male or female. Notice that arithmetic operations cannot be performed on these attributes.

question

Distinguishing between Qualitative and Quantitative Variables (b) Temperature

answer

(b) Temperature is a quantitative variable because it is numeric, and operations such as addition and subtraction provide meaningful results. For example, 70°F is 10°F warmer than 60°F.

question

Distinguishing between Qualitative and Quantitative Variables (c) Number of days during the past week that a college student aged 21 years or older has had at least one drink

answer

(c) Number of days during the past week that a college student aged 21 years or older had at least one drink is a quantitative variable because it is numeric, and operations such as addition and subtraction provide meaningful results.

question

Distinguishing between Qualitative and Quantitative Variables (d) Zip code

answer

(d) Zip code is a qualitative variable because it categorizes a location. Notice that, even though they are numeric, the addition or subtraction of zip codes does not provide meaningful results.

question

discrete variable

answer

is a quantitative variable that has either a finite number of possible values or a countable number of possible values. The term countable means that the values result from counting, such as 0, 1, 2, 3, and so on.

question

continuous variable

answer

is a quantitative variable that has an infinite number of possible values that are not countable.

question

Distinguishing between Discrete and Continuous Variables (a) The number of heads obtained after flipping a coin five times.

answer

(a) The number of heads obtained by flipping a coin five times would be a discrete variable because we would count the number of heads obtained. The possible values of the discrete variable are 1,2,3,4...

question

Distinguishing between Discrete and Continuous Variables (b) The number of cars that arrive at a McDonald's drive-through between 12:00 P.M. and 1:00 P.M.

answer

(b) The number of cars that arrive at a McDonald's drive-through between 12:00 P.M. and 1:00 P.M. is a discrete variable because its value would result from counting the cars. The possible values of the discrete variable are 0, 1, 2, 3, 4, and so on. Notice that there is no predetermined upper limit to the number of cars that may arrive.

question

Distinguishing between Discrete and Continuous Variables (c) The distance a 2007 Toyota Prius can travel in city driving conditions with a full tank of gas.

answer

(c) The distance traveled is a continuous variable because we measure the distance.

question

The type of variable (qualitative, discrete, or continuous) dictates

answer

the methods that can be used to analyze the data.

question

nominal level of measurement

answer

if the values of the variable name, label, or categorize. In addition, the naming scheme does not allow for the values of the variable to be arranged in a ranked or specific order.

question

ordinal level of measurement

answer

if it has the properties of the nominal level of measurement and the naming scheme allows for the values of the variable to be arranged in a ranked or specific order.

question

interval level of measurement

answer

if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero in the interval level of measurement does not mean the absence of the quantity. Arithmetic operations such as addition and subtraction can be performed on values of the variable.

question

ordinal level of measurement

answer

if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero in the interval level of measurement does not mean the absence of the quantity. Arithmetic operations such as addition and subtraction can be performed on values of the variable.

question

ratio level of measurement

answer

if it has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero in the ratio level of measurement means the absence of the quantity. Arithmetic operations such as multiplication and division can be performed on the values of the variable.

question

Determining the Level of Measurement of a Variable. (a) Gender

answer

(a) Gender is a variable measured at the nominal level because it only allows for categorization of male or female. Plus, it is not possible to rank gender classifications.

question

Determining the Level of Measurement of a Variable. (b) Temperature

answer

(b) Temperature is a variable measured at the interval level because differences in the value of the variable make sense. For example, 70°F is 10°F warmer than 60°F. Notice that the ratio of temperatures does not represent a meaningful result. For example, 60°F is not twice as warm as 30°F. In addition, 0°F does not represent the absence of heat.

question

Determining the Level of Measurement of a Variable. (c) Number of days during the past week that a college student aged 21 years or older has had at least one drink

answer

(c) Number of days during the past week that a college student aged 21 years or older has had at least one drink is measured at the ratio level, because the ratio of two values makes sense and a value of zero has meaning. For example, a student who had four drinks had twice as many drinks as a student who had two drinks.

question

Determining the Level of Measurement of a Variable. (d) Letter grade earned in your statistics class

answer

(d) Letter grade is a variable measured at the ordinal level because the values of the variable can be ranked, but differences in values have no meaning. For example, an A is better than a B, but A - B has no meaning.

question

Validity

answer

of a variable or measurement represents how close to the true value the measurement is. In other words, a variable is valid if it measures what it is supposed to measure.

question

Reliability

answer

of a variable or measurement represents the ability of different measurements of the same individual to yield the same results

question

A(n)_____________ is a person or object that is a member of the population being studied

answer

individual

question

A(n) _____ is a numerical summary of sample. A(n)_____ is a numerical summary of a population.

answer

A(n) statistic is a numerical summary of sample. A(n) parameter is a numerical summary of a population.

question

determine whether the underlined value is a parameter or a statistic. State Government Following the 2006 national midterm election, 18% of the governors of the 50 United States were female.

answer

parameter

question

determine whether the underlined value is a parameter or a statistic. Illegal Drugs In a national survey of high school students (grades 9 to 12), 25% of respondents reported that someone had offered, sold, or given them an illegal drug on school property.

answer

statistic

question

determine whether the underlined value is a parameter or a statistic. Batting Average Ty Cobb is one of Major League Baseball's greatest hitters of all time, with a career batting average of 0.366

answer

parameter

question

determine whether the underlined value is a parameter or a statistic. Hygiene Habits A study of 6,076 adults in public rest rooms (inAtlanta,Chicago,NewYork City,and San Francisco) found that 23% did not wash their hands before exiting.

answer

statistic

question

classify the variable as qualitative or quantitative. Nation of origin

answer

qualitative

question

classify the variable as qualitative or quantitative. Grams of carbohydrates in a doughnut

answer

quantitative

question

classify the variable as qualitative or quantitative. Number of unpopped kernels in a bag of ACT microwave popcorn

answer

quantitative

question

classify the variable as qualitative or quantitative. Phone number

answer

qualitative

question

determine whether the quantitative variable is discrete or continuous. Runs scored in a season by Albert Pujols

answer

discrete

question

determine whether the quantitative variable is discrete or continuous Length (in minutes) of a country song

answer

continuous

question

determine whether the quantitative variable is discrete or continuous Temperature on a randomly selected day in Memphis, Tennessee

answer

continuous

question

determine whether the quantitative variable is discrete or continuous Points scored in an NCAA basketball game

answer

discrete

question

determine the level of measurement of each variable. Nation of origin

answer

Nominal

question

determine the level of measurement of each variable. Volume of water used by a household in a day

answer

Ratio

question

determine the level of measurement of each variable. Highest degree conferred (high school, bachelor's, and so on)

answer

ordinal

question

determine the level of measurement of each variable. Assessed value of a house

answer

Ratio

AP Statistics
Least Squares Regression
Statistics

Stats Multiple Choice – Flashcards 43 terms
Alexander Rose

43 terms
Preview

Stats Multiple Choice – Flashcards

question

Suppose that sixteen-ounce bags of chocolate chip cookies are produced with an actual mean weight of 16.1 ounces and a standard deviation of 0.1 ounce. The percentage of bags that will contain between 16.0 and 16.1 ounces is a. 10 b. 16 c. 34 d. 68 e. none of the above

answer

c

question

Which statement is true for any density curve? a. The bars must be of equal width. b. It is symmetric. c. It must either steadily rise or steadily fall, since it cannot do both. d. One can use Table A (table of standard normal values) to find relative frequencies. e. None of the above is correct.

answer

e

question

Increasing the frequencies in the tails of a distribution will: a. Not affect the standard deviation as long as the increases are balanced on each side of the mean b. not affect the standard deviation c. Increase the standard deviation d. reduce the standard deviation e. none of the above

answer

c

question

Which of the following are true statements? I. The area under a normal curve is always 1, regardless of the mean and standard deviation. II. The mean is always equal to the median for any normal distribution. III. The interquartile range for any normal curve extends from (mean-1 standard deviation) to (mean+1standard deviation) a. I and II b. I and III c. II and III d. I, II, and III e. None of the above gives the correct set of true responses

answer

a

question

Pop1 and Pop2 are normal density curves with means and standard deviations mean1, st dev1, and mean2, st dev2, respectively. Suppose that mean1=mean2 and st dev1=2(st dev2). Consider these statements: I. Pop1 has twice as many observations within one standard deviation of the mean as Pop2. II. The density curve for Pop1 is taller than that of Pop2. III. The density curves are centered around different numbers. Which of these statements are correct? a. I only b. II only c. III only d. I and II only e. None of the above gives the correct set of true responses

answer

e

question

A researcher wishes to calculate the average height of patients suffering from a particular disease. From patient record, the mean was computed as 156cm, and the standard deviation as 5cm. Further investigation reveals that the scale was misaligned, and that all readings are 2cm too large, for example, a patient whose height is really 180cm was measured as 182cm. Furthermore, the researcher would like to work with statistics based on meters. The correct mean and standard deviation are: a. 1.56m, .05m b. 1.54m, .05m c. 1.56m, .03m d. 1.58m, .05m e. 1.58m, .07m

answer

b

question

A medical researcher collects health data on many women in each of several countries. One of the variables measure for each woman in the sudy is her weight in pounds. The following list gives the five-number summary for the weights of women in one of the countries. Country A: 100, 110, 120, 160, 200 About what percentage of country A women weight between 110 and 200 pounds? a. 50% b. 65% c. 75% d. 85% e. 95%

answer

c

question

The mediam age of five people in a meeting is 30 years. One of the people, whose age is 50 years, leaves the room. THe mediam age of the remaining four people in the room is: a. 40 years b. 30 years c. 25 year d. less than 30 years e. Cannot be determined from the information given

answer

e

question

Earthquake intensities are measured using a device called a seismograph, which is designed to be most sensitive for earthquakes with intensities between 4.0 and 9.0 on the open-ended Richter scale. Measurements of nine earthquakes gave the following readings: 4.5 L 5.5 H 8.7 8.9 6.0 H 5.2 Where L indicates that the earthquake had an intensity below 4.0 and an H indicates that the earthquake had an intensity above 9.0. The median earthwuake intensity of the sample is a. Cannot be computed since all of the values are not known b. 8.70 c. 5.75 d. 6.00 e. 6.47

answer

d

question

The probability of any outcome of a random phenomenon is a. the precise degree of randomness present in the phenomenon b. any number as long as it is between 0 and 1 c. Either 0 or 1, depending on whether or not the phenomenon can actually occur or not d. The proportion of a very long series of repetitions on which the outcome occurs e. none of the above

answer

d

question

A randomly elected student is asked to respond to yes, no, or maybe to the question, "Do you intend to vote in the next presidential election?" The sample space is {yes, no, maybe}. Which of the following represent a legitimate assignment of probabilities for this sample space? a. 0.4, 0.4, 0.2 b. 0.6, 0.6, 0.4 c. 0.3, 0.3, 0.3 d. 0.5, 0.3, -0.2 e. None of the above

answer

a

question

If you choose a card at random from a well-shuffled deck of 52 cards, what is the probability that the card chosen is not a heart? a. 0.25 b. 0.5 c. 0.75 d. 1 e. none of the above

answer

c

question

You play tennis regularly with a friend, and from past experience, you believe that the outcome of each match is independent. For any given match you have a probability of .6 of winning. The probability that you win the next two matches is a. 0.16 b. 0. 36 c. 0.4 d. 0.6 e. 1.2

answer

b

question

If P(A)=0.24 and P(B)=0.52 and A and B are independent, what is P(A or B)? a. 0.1248 b. 0.28 c. 0.6352 d. 0.76 e. The answer cannot be determined from the information given.

answer

c

question

What is meant by disjoint (mutually exclusive) events?

answer

When two events share no outcomes.

question

Define complementary events

answer

When two events go along with each other to add up to 1.

question

Suppose we fit the least squares regression line to a set of data. What do we call any individual points with unusually large values of the residuals? a. response variables b. the slope c. outliers d. correlations e. none of the above

answer

c

question

If removing an observation from a data set would have a marked change on the position of the LSRL fit to the data, what is the point called: a. robust b. a residual c. a response d. influential e. none of the above

answer

d

question

Which of the following statements are correct? I. Two variables that are strongly associated will have a correlation near 1 II. Regression requires an explanatory-response relationship, while correlation does not. III. Even though the correlation between two variables may be high, in order to use the LSRL to predict, there needs to be an explanatory-response relationship between x and y. a. I and II only b. I and III only c. II and III only d. I, II, III e. None of the above gives the complete set of true responses.

answer

c

question

Recent data show that states that spend an above-average amount of money X per pupil in high school tend to have below-average mean Verbal SAT scores Y of all students taking the SAT in the state. In other words, there is a negative association between X (spending per pupil) and Y (mean Verbal SAT score). High spending per pupil and low mean verbal SAT scores are particularly common in states that have a large percentage of all high school students takking the exam. Such states also tend to have a larger populations. The most plausible explanation for the observed association between X and Y is that a. X causes Y. Overspending generally leads to extra, unnecessary programs, diverting attention from basic subjects. Inadequate training in these basic subjects generally leads to lower SAT scores. b. Y causes X. Low SAT scores create concerns about the quality of education. This inevitably leads to additional spending to help solve the problem. c. changes in X and Y are due to a common response to other variables. If a higher percentage of students take the exam, the average score will be lower. Also, states with larger populations have large urban areas where the cost of living is higher and more money is needed for expenses. d. the association between X and Y is purely coincidental. it is implausible to believe the observed association could be anything other that accidental.

answer

c

question

A researcher notices that in a sample of adults, those that take larger amount of vitamin C have fewer illnesses. However, those that take larger amounts of vitamin C also tend to exercise more. As explanations for having fewer illnesses, the variables "amount of vitamin C taken" and "amount of exercise" are a. skewed b. confounded c. common responses d. symmetric

answer

b

question

What do we call a sample that consists of the entire population? a. stratum b. a multistage sample c. a mistake. A sample can never be the entire population d. a census e. none of the above

answer

d

question

A member of Congress wants to know what his constituent think of proposed legislation on health insurance. His staff reports that 228 letters have been received on the subject, of which 193 oppose the legislation. What is the population in this situation? a. the constituents b. the 228 letters received c. the 193 opposing the legislation d. Congress e. None of the above

answer

a

question

Which of the following is a method for improving the accuracy of a sample? a. Use no more than 3 or 4 words in any question b. When possible, avoid the use of human interviewers, relying on computerized dialing instead c. Use large sample sizes d. Use smaller sample sizes e. None of the above.

answer

c

question

We say that the design of a study is biased if which of the following is true? a. A racial or sexual preference b. Random placebos have been used c. certain outcomes are systematically favored. d. The correlation is greater that 1 or less than -1 e. none of the above.

answer

c

question

Control groups are used in experiments in order to... a. control the effects of lurking variables such as the placebo b. control the subjects of a study so as to insure all participate equally c. guarantee that someone other than the investigators, who have a vested interest in the outcome, control how the experiment is conducted d. achieve a proper and uniform level of randomization e. none of theabove

answer

a

question

Suppose the Richmond-Times dispatch asks a sample of 150 Richmonders their opinions on the quality of life in Richmond. is this study an experiment? Why or why not?

answer

No, a treatment is not imposed

question

In a statistics course, a linear regression equation was computed to predict the final exam score from the score on the first test. The equation was y=10+0.9x where y is the final exam score and x is the score on the first test. Carla scored 95 on the first test. What is the predicted value of her score on the final exam? a. 95 b. 85.5 c. 90 d. 95.5 e. none of the above

answer

d

question

In a statistics course, a linear regression equation was computed to predict the final exam score from the score on the first test. The equation was y=10+0.9x where y is the final exam score and x is the score on the first test. On the final exam Carla scored 98. What is the value of her residual? a. 98 b. 2.5 c. -2.5 d. 0 e. none of the above

answer

b

question

All but one of the following statements contains a blinder. Which statement is correct? a. The is a correlation of 0.54 between the position of a football player plays and his weight. b. The correlation between planting rate and yield of corn was found to be r=0.23. c. The correlation between the gas milage of a car and its weight is r=0.71 MPG d. We found a high correlation (r=1.09) between the height and age of children. e. We found a correlation of r=-.63 between gender and political party preference.

answer

b

question

In general, is correlation a resistant measure of association?

answer

no

question

Is the least-squares regression line resistant? Why?

answer

no, influential points effect it.

question

In a large population of college students, 20% of the students have experienced feelings of math anxiety. If you take a random sample of 10 students from this population, the probability that exactly 2 students have experienced math anxiety is a. 0.3020 b. 0.2634 c. 0.2013 d. 0.5 e. 1 f. none of the above

answer

a

question

In a large population of college students, 20% of the students have experienced feelings of math anxiety. If you take a random sample of 10 students from this population, the standard deviation of of the number of students in the sample who have experienced math anxiety is a. 0.0160 b. 1.265 c. 0.2530 d. 1 e. .2070

answer

b

question

In a certain population, 40% of households have a total annual income of $70,000. A simple random sample of 4 of these households is selected. What is the probability that 2 or more of the households in the survey have an annual income of over $70,000? a. 0.34565 b. 0.4000 c. 0.5000 d. 0.5248 e. The answer cannot be computed from the information given

answer

d

question

A factory makes silicon chips for use in computers. It is known that about 90% of the chips meet specifications. Every hour a sample of 18 chips is selected at random for testing. Assume a binomial distribution is valid. Suppose we collect a large number of these samples of 18 chips and determine the number meeting specifications in each sample. What is the approximate mean of the number of chips meeting specifications? a. 16.20 b. 1.62 c. 4.02 d. 16.00 e. The answer cannot e computed from the information given.

answer

a

question

Which of the following are true statements? I. The expected value of a geometric random variable is determined by the formula p(1-p)^n-1 II. If X is a geometric random variable and the probability of success is .85, then the probability distribution of X will be skewed left, snince 85 is closer to 1 than to 0. III.. An important difference between binomial and geometric random variables is that there is a fixed number of trials in a binomial setting, and the number of trials varies in a geometric setting. a. I only b. II only c. III only d. I, II, and III e. None of the above gives the complete set of true responses

answer

c

question

Describe the four conditions that describe a binomial setting.

answer

1. set n trials 2. success or failure (2 outcomes) 3. independent trials 4. p always stays the same

question

Suppose X is a random variable with a mean. Suppose we observe X many times and keep track of the average of the observed values. The law of large numbers says that a. The value of mean will get larger and larger as we observe X b. As we observe X more and more, this average and the value of mean with get larger and larger. c. This average will get closer and closer to the mean as we observe X more and more often. d. as we observe X more and more, this average will get to be a larger and larger multiple of mean. e. none of the above

answer

c

question

In a population of students, the number of calculators owned is a random variable X with P(X=0)=0.2, P(X=1)=0.6, and P(X=2)=0.2. The mean of this probability distribution is a. 0 b. 2 c. 1 d. 0.5 e. The answer cannot be computed from the imformation given

answer

c

question

In a population of students, the number of calculators owned is a random variable X with P(X=0)=0.2, P(X=1)=0.6, and P(X=2)=0.2. The variance of this probability distribution is a. 1 b. 0.63 c. 0.5 d. 0.4 e. the answer cannot be computed from the information given

answer

d

question

The number of calories in a one0ounce serving of a certain breakfast cereal is a random variable with mean 110. The number of calories in a full cup of whole milk is a random variable with mean 140. for breakfast you eat one ounce of the cereal with 1/2 cup of whole milk. Let Z be the random variable that represents the total number of calories in the breakfast. The mean of Z is a. 110 b. 140 c. 180 d. 250 e. 195

answer

c

question

The weight of reports produced in a certain department has a normal distribution with mean 60g and standard deviation 12g. What is the probability that the next report will weight less than 45g? a. 0.1042 b. 0.1056 c. 9,3944 d. 0.0418 e. The answer cannot be computed from the information given

answer

b

AP Statistics
Statistics

AP Stats Midterm – Flashcards 107 terms
Jamie Hutchinson

107 terms
Preview

AP Stats Midterm – Flashcards

question

1. In an experiment, an observed effect so large that it would rarely occur by chance is called

answer

statistically significant

question

2. Which statements below about the least-squares regression line are correct?I. Switching the explanatory and response variables will not change the least-squares regression line.II. The slope of the line is very sensitive to outliers with large residuals.III. A value of r2 close to 1 does not guarantee that the relationship between the variables is linear

answer

Both II and III are correct

question

3. A set of data describes the relationship between the size of annual salary raises and the performance ratings for employees of a certain company. The least squares regression equation is y=1400 + 2000x where y is the raise amount (in dollars) and x is the performance rating. Which of the following statements is not necessarily true

answer

The actual relationship between salary raises and performance rating is linear

question

4. The cumulative relative frequency graph below shows the distribution of lengths (in centimeters) of fingerlings at a fish hatchery. The interquartile range for this distribution is approximately

answer

1.2 centimeters

question

5. The heights of American men aged 18 to 24 are approximately normally distributed with a mean of 68 inches and a standard deviation of 2.5 inches. Only about 5% of young men have heights outside the range

answer

63 inches to 73 inches

question

6. The distribution of the time it takes for different people to solve a certain crossword puzzle is strongly skewed to the right, with a mean of 30 minutes and a standard deviation of 15 minutes. The distribution of z-scores for those times is

answer

Skewed to the right, with mean 0 and standard deviation 1

question

7. What is the distribution of values taken by a statistic in all possible samples of the same size from the same population called

answer

The sampling distribution of the statistic

question

8. The weights of the male and female students in a class are summarized in the following boxplot. Which of the following is NOT correct

answer

The male students have less variability than the female students

question

9. A rock concert producer has scheduled an outdoor concert. If it is warm that day, she expects to make a $20,000 profit. If it is cool that day, she expects to make a $5000 profit. If it is very cold that day, she expects to suffer a $12,000 loss. Based upon historical records, the weather office has estimated the chances of a warm day to be 0.60; the chances of a cool day to be 0.25. What is the producer's expected profit

answer

$11,450

question

10. A dealer in the Sands Casino in Las Vegas selects 40 cards from a standard deck of 52 cards. Let Y be the number of red cards (hearts or diamonds) in the 40 cards selected. Which of the following best describes this setting

answer

Y has a binomial distribution with n=40 observations and probability of success p=0.5, provided that after selecting a card it is replaced in the deck and the deck is shuffled well before the next card is selected

question

11. The graph below is a normal probability plot for the amount of rainfall (in acre-feet) obtained from 26 randomly selected clouds that were seeded with silver oxide. Which of the following statements about the shape of the rainfall distribution is true

answer

The distribution is skewed right

question

12. You take a sample of size 25 from a very large population in which the true proportion is p=0.1, thus violating the condition that np>10 and n(1-p)>10. Which statement below best describes what you know about the sampling distribution of p

answer

Mean=0.1; S(x)=(0.1*0.9)/25)^.5; the distribution is not approximately Normal

question

13. To test the effect of music on productivity, a group of assembly line workers are given portable mp3 players to play whatever music they choose while working for one month. For another month, they work without music. The order of the two treatments for each worker is determined randomly. This is

answer

A matched pairs experiment

question

14. Use the information in the previous problem. About what percentage of men are over 70.5 inches tall

answer

16

question

15. A vending machine operator has determined that the number of candy bars sold per week by a certain machine is a random variable with mean 125 and standard deviation 7. His profit on each bar sold is $0.25, and it costs him $5.00 per day to maintain the machine and rent the space for it. What are the mean and standard deviation for Y=the profit he earns from this machine in a randomly-selected week

answer

Mean=26.25, standard deviation=$1.75

question

16. Which of these variables is least likely to have a normal distribution

answer

Annual income for all 150 employees at a local high school

question

17. People with type O-negative blood are universal donors. That is, any patient can receive a transfusion of O-negative blood. Only7.2% of the American population has O-negative blood. If 10 people appear at random to give blood, what is the probability that at least one of them is a universal donor

answer

0.526

question

18. A student investigating study habits asks a simple random sample of 16 students at her school how many minutes they spent on their English homework the previous night. Suppose the actual parameter values for this variable are mean=45 minutes and s(x)=15 minutes. Which of the following best describes what we know about the sampling distribution of means for the student's sample

answer

mean=45, s(x)=3.75, shape of distribution unknown

question

19. A public opinion poll in Ohio wants to determine whether or not registered voters in the state approved of a measure to ban smoking in all public areas. They select a simple random sample of fifty registered voters from each county in the state and ask whether they approve or disapprove of the measure. This is an example of a

answer

stratified random sample

question

20. When testing water for chemical impurities, results are often reported as bdl, that is, below detection limit. The following are the measurements of the amount of lead in a series of water samples taken from inner-city households (in parts per million); 5, 7, 12, bdl, 10, 8, bdl, 20, 6

answer

The median lead level in the water is 7 ppm

question

21. A college basketball player makes 80% of her free throws. At the end of the game, her team is losing by two points. She is fouled attempting a three-point shot and is awarded three free throws. Assuming free throw attempts are independent, what is the probability that she makes at least two of her free throws

answer

0.896

question

22. A small company estimating its photocopying expenses finds that the mean number of copies made per day for the past 12 months is 258 copies per day with a standard deviation of 24 copies per day. Which of the following is a correct interpretation of standard deviation

answer

on average, the number of copies made each day was about 24 copies per day away from the mean, 258

question

23. In some courses (but certainly not in an intro stats course!), students are graded on a "Normal curve." For example, students within +/- 0.5 standard deviations of the mean receive a C; between 0.5 and 1.0 standard deviations above the mean receive a C+; between 1.0 and 1.5 standard deviations above the mean receive a B-; between 1.5 and 2.0 standard deviations above the mean receive a B, etc. The class average on an exam was 60 with a standard deviation of 10. The bounds for a B- grade and the percent of students who will receive a B- grade if the marks are actually Normally distributed are

answer

(70,75), 9.19%

question

24. Which of the following random variables is geometric

answer

The number of digits I will read beginning at a randomly selected starting point in a table of random digits until I find a 7

question

25. A small company that prints custom T-shirts has 6 employees, one of whom is the owner and manager. Suppose the owner makes $120,000 per year and the other employees make between $40,000 and $50,000 per year. One day, the owner decides to give himself a $30,000 raise. Which of the following describes how the company's mean and median salaries would change

answer

the mean would increase by $5,000 and the median would not change

question

26. The 16th percentile of a Normally distributed variable has a value of 25 and the 97.5th percentile has a value of 40. Which of the following is the best estimate of the mean and standard deviation of the variable

answer

mean=30, s(x)=5

question

27. If a distribution is skewed to the right, which of the following is true

answer

the mean must not be greater than the median

question

28. The sampling distribution of a statistic is

answer

the distribution of values taken by a statistic in all possible samples of the same sample size from the same population

question

29. The five-number summary for scores on a statistics test is 11, 35, 61, 70, 79. In all, 380 students took the test. About how many scored between 35 and 61

answer

95

question

30. A maple sugar manufacturer wants to estimate the average trunk diameter of Sugar Maples trees in a large forest. There are too many trees to list them all and take an SRS, so he divides the forest into several hundred 10 meter by 10 meter plots, selects 25 plots at random, and measures the diameter of every single Sugar Maple in each one. This is an example of a

answer

cluster sample

question

31. The best statistic for estimating a parameter has which of the following characteristics

answer

low bias, low variability

question

32. An experiment to measure the effect of giving growth hormones to girls affected by Turner's Syndrome was carried out recently in Vancouver. All 34 girls were given the growth hormone and their heights were measured at the time the hormone was given and again one year later. No measurements were made on their final adult heights. Which of the following is not a problem with this experiment

answer

nonresponse bias

question

33. The incomes in a certain large population of college teachers have a normal distribution with mean $60,000 and standard deviation $5000. Four teachers are selected at random from the population to serve on a salary review committee. What is the probability that their average salary exceeds $65,000

answer

0.0228

question

34. You are interested in predicting the cost of heating houses on the basis of how many rooms the house has. A scatterplot of 25 houses reveals a strong linear relationship between these variables, so you calculate a least-squares regression line. "Least-squares" refers to

answer

minimizing the sum of the squares of the residuals

question

35. There are 10 red marbles and 8 green marbles in a jar. If you take three marbles from the jar (without replacement), the probability that they are all red is

answer

0.147

question

36. Experience has shown that a certain lie detector will show a positive reading (indicates a lie) 10% of the time when a person is telling the truth and 95% of the time when a person is lying. Suppose that a random sample of 5 suspects is subjected to a lie detector test regarding a recent one-person crime. Then the probability of observing no positive readings if all suspects plead innocent and are telling the truth is

answer

0.591

question

37. You work for an advertising agency that is preparing a new television commercial to appeal to women. You have been asked to design an experiment to compare the effectiveness of three versions of the commercial. Each subject will be shown one of the three versions and then asked her attitude toward the product. You think there may be large differences between women who are employed outside the home and those who are not. Because of these differences, you should use

answer

a block design

question

38. Control groups are used in experiments in order to

answer

control the effects of outside variables on the outcome

question

39. Select a random integer from -100 to 100. Which of the following pairs of events are mutually exclusive (disjoint)

answer

A-the number is above 50 and B-the number is less than 20

question

40. Mr. Nerdly asked the students in his AP Statistics class to report their overall grade point averages and their SAT Math scores. The scatterplot below provides information about his students' data. The dark line is the least-squares regression line for the data, and its equation is y=410.54+67.3x. Which of the following about the circled point is false

answer

removing the student's data point would increase the slope of the least-squares line

question

41. In a statistics course, a linear regression equation was computed to predict the final exam score from the score on the first test. The equation was y=10+0.9x where y is the final exam score and x is the score on the first test. Carla scored 95 on the first test. What is the predicted value of her score on the final exam

answer

95.5

question

42. Which of the following properties is true for all Normal density curves? I. They are symmetric II. The curve reaches its peak at the meanIII. 95% percent of the area under the curve is within one standard deviation of the mean

answer

I and II only

question

43. If PA=0.24 and PB=0.52 and A and B are independent, what is P(A or B)

answer

0.6352

question

44. The distribution of the heights of students in a larger class is roughly Normal. Moreover, the average height is 68 inches, and approximately 95% of the heights are between 62 and 74 inches. Thus, the standard deviation of the height distribution is approximately equal to

answer

3

question

45. If a store runs out of advertised material during a sale, customers become upset, and the store loses not only the sale but also goodwill. From past experience, a music store finds that the mean number of CDs sold in a sale is 845, the standard deviation is 15, and a histogram of the demand is approximately Normal. The manager is willing to accept a 2.5% chance that a CD will be sold out. About how many CDs should the manager order for the sale

answer

875

question

46. A medical researcher collects health data on many women in each of several countries. One of the variables measured for each woman in the study is her weight in pounds. The following list gives the five-number summary for the weights of adult women in one of the countries. Country A-92,110,120,160,240. About what percent of Country A women weight between 110 and 240 pounds

answer

75%

question

47. Which of the following statements is/are true when taking an SRS from a large population? I. The sampling distribution of x has standard deviation s(x)/sq root of , even if the population is not Normally distributed. II. The sampling distribution of x is Normal if the population has a Normal distribution. III. When n is large, the sampling distribution of x is approximately normal even if the population is not Normally distributed

answer

I,II, and III

question

48. In order to use the formula s(X)=s(x)/sq. root of n to calculate the standard deviation of the sampling distribution of the sample mean, which of the following conditions must be met? I. N>30 II. The population's distribution is approximately Normal. III. The sample size is less than 10% of the population size

answer

III only

question

49.A randomly chosen subject arrives for a study of exercise and fitness. Consider these statements. I. After 10 minutes on an exercise bicycle, you ask the subject to rate his or her effort on the rate of perceived exertion (RPE) scale. RPE ranges in whole-number steps from 6 (no exertion at all) to 20 (maximum exertion). II. You measure VO2, the maximum volume of oxygen consumed per minute during exercise. VO2 is generally between 2.5 liters per minute and 6 liters per minute. III. You measure the maximum heart rate (beats per minute). The statements that describe a discrete random variable are

answer

I,III.

question

50. Which of the following statements are true? I. The area under the Normal curve is always 1, regardless of the mean and standard deviation. II. The mean is always equal to the median for any Normal distribution. III. The interquartile range for any Normal curve extends from mean-S(x) to mean+s(x)

answer

I and II

question

51. Here are the IQ test scores of 10 randomly chosen fifth-grade students-145,139,126,122,125,130,96,110,118,118. To make a stemplot of these scores, you would use as stems

answer

09,10,11,12,13, and 14.

question

52. Use scenario 6-13. Which of the following is the mean of X

answer

600

question

53. Use scenario 6-13. Which of the following is the approximate standard deviation of X

answer

19

question

54. Kitchen appliances don't last forever. The lifespan of all microwave ovens sold in the United States is approximately Normally distributed with a mean of 9 years and a standard deviation of 2.5 years. What percentage of the ovens last more than 10 years

answer

34.5%

question

55. Of people who died in the United States in a recent year, 86% were white, 12% were black, and 2% were Asian. (We will ignore the small number of deaths among other races.) Diabetes caused 2.8% of deaths among whites, 4.4% among blacks, and 3.5% among Asians. The probability that a randomly chosen death was due to diabetes is about

answer

0.030

question

56. The security system in a house has two units that set off an alarm when motion is detected. Neither one is entirely reliable, but one or both always go off when there is motion anywhere in the house. Suppose that for motion in a certain location, the probability that detector A goes off and detector B does not go off is 0.25, and the probability that A does not go off is 0.35. What is the probability that B goes off

answer

0.75

question

57. According to a 1990 census, those states with an above-average number of people X, who fail to complete high school tend to have an above average number of infant deaths, Y. In other words, there is a positive association between X and Y. The most plausible explanation for this is

answer

Lurking variables are probably present. For example, states with large populations may have both larger numbers of people who don't complete high school and more infant deaths.

question

58. The probability of any outcome of a random phenomena is

answer

the proportion of times the outcome occurs in a very long series of repetitions

question

59. The probability that a randomly selected household has at least 2 cell phones is

answer

0.80.

question

60. A double-blind experiment was conducted to evaluate the effectiveness of the Salk polio vaccine. The purpose of keeping the diagnosing physicians ignorant of the treatment status of the experimental subjects was to

answer

eliminate the possible source of bias

question

61. Use Scenario 5-13. You select one student from this group at random. If the student says he is a junior, what is the probability that he walks to school

answer

0.160

question

62. Use Scenario 5-13. You select one student from the group at random. Which of the following statements is true about the events "Typically walks to school" and Junior

answer

the events are not mutually exclusive but they are independent

question

63. Following a dramatic drop of 500 points in the Dow Jones Industrial Average in September 1998, a poll conducted for the Associated Press found that 92% of those polled said that a year from now their family financial situation will be as good as it is today or better. Which of the following terms describes the number 92%

answer

statistic

question

64. Other things being equal, larger automobile engines consume more fuel. You are planning an experiment to study the effect of engine size (in liters) on the gas mileage (in miles per gallon) of sport utility vehicles. In this study

answer

gas mileage is a response variable, and you expect to find a negative association

question

65. You have data for many families on the parents' income and the years of education their eldest child completes. Your initial examination of the data indicates that children from wealthier families tend to go to school for longer. When you make a scatterplot

answer

the explanatory variable is parents' income, and you expect to see a positive association

question

66. Which of the following is a true statement

answer

an important difference between binomial and geometric random variables is that there is a fixed number of in a binomial setting, and the number of trials varies in a geometric setting

question

67. The reason that blocking (in a randomized block design) is sometimes used in experimentations is to

answer

reduce variability arising from random assignment

question

68. A copy machine dealer has data on the number of copy machines x at each of 89 customer locations and the number of service calls in a month y at each location. Summary calculations give x-bar=8.4, s(x)=2.1, y-bar=14.2, s(y)=3.8, and r=0.86. What is the slope of the least-squares regression line of number of service calls on number of copies

answer

1.56

question

69. The central limit theorem refers to which of the following characteristics of the sampling distribution of the sample mean

answer

regardless of the shape of the population's distribution, the sampling distribution of the sample mean from sufficiently large samples will be approximately normally distributed

question

70. If you buy one ticket in the Provincial Lottery, then the probability that you will win a prize is 0.11. Given the nature of lotteries, the probability of winning is independent from month to month. If you buy one ticket each month for five months, what is the probability that you will win at least one prize

answer

0.44

question

71. If A=result of a single roll of a six-sided die and B=result of a single roll of an 8-sided die, then meanA=3.5, S(a)=1.71, meanB=4.5, and S(b)=2.29. If D=the difference B-A, then which of the following is true

answer

meanD=1, S(d)=sq root(1.71)²+(2.29)²

question

72. Jun and Deron are applying for summer jobs at a local restaurant. After interviewing them, the restaurant owner says, "The probability that I hire Jun is 0.7, and the probability that I hire Deron is 0.4. The probability that I hire at least one of you in 0.9." What is the probability that both Jun and Deron get hired

answer

0.2

question

73. A nutritionist wants to study the effect of storage time (6,12, and 18 months) on the amount of vitamin C present in freeze dried fruit when stored for these lengths of time. Vitamin C is measured in milligrams per 100 milligrams of fruit. Six fruit packs were randomly assigned to each of three storage times. The treatment, experimental unit, and response are respectively

answer

a specific storage time, a fruit pack, amount of vitamin C

question

74. A materials engineer wishes to compare the durability of two different types of paving material. She has 40 different one-mile stretches of interstate highway that she's been authorized to repave for the study. She decides to carry out a matched-pairs experiment. Which of the following is the best way for her to carry out the randomization for this study

answer

let each of the 40 roadways act as its own pair, dividing each roadway into the first half-mile and second half-mile. Flip a coin for each of the 40 roadways to decide which half-mile gets which pavement

question

75. The variance of sum of two random variables X and Y is

answer

(s(x)2 + (s(y)2, but only if X and Y are independent

question

76. We say that the design of a study is biased if which of the following is true

answer

certain outcomes are systematically favored

question

77. Roll one 8-sided die 10 times. The probability of getting exactly 3 sevens in those 10 rolls is given by

answer

(10/3)(1/8)^3(7/8)^7

question

78. Let the random variable X represent the weight of male black bears before they begin hibernation. Research has shown that X is approximately Normallly distributed with a mean of 250 pounds and a standard deviation of 50 pounds. What is P(x>325 pounds)

answer

0.0668.

question

79. The mean speed of vehicles in the "cars only" lane of the New Jersey turnpike is 68 miles per hour. The mean speed of vehicles in the "any vehicle" lane is 64 miles per hour. What must be true about the mean speed of all vehicles on the turnpike, assuming these are the only types of lanes

answer

It could be any number between 64 and 68 miles per hour

question

80. If your score on the test is at the 60th percentile, you know that your score lies

answer

between the median and the third quartile

question

81. A fair coin is tossed four times, and each time the coin lands heads up. If the coin is then tossed 1996 more times, how many heads are most likely to appear in these 1996 additional tosses

answer

998

question

82. Which of the following is a method for improving the accuracy of a sample

answer

use larger sample sizes

question

83. Mr. Yates picked up a dozen items in the grocery store with a mean cost of $3.25. Then he added an apple pie for $6.50. The new mean for all 13 items is

answer

$3.50

question

84. If a statistic is used to estimate a parameter is such that the mean of the sampling distribution is equal to the true value of the parameter being estimated, what is the statistic said to be

answer

unbiased

question

85. You draw two marbles at random from a jar that has 20 red marbles and 30 black marbles without replacement. What is the probability that both marbles are red

answer

0.1551

question

86. Event A occurs with probability 0.2. Event B occurs with probability 0.8. If A and B are disjoint (mutually exclusive), then

answer

P(A or B)=1.0

question

87. A least-squares regression line for predicting weights of basketball players on the basis of their heights produced the residual plot below. What does the residual tell you about the linear model

answer

the curved pattern in the residual plot suggests that the linear model is not appropriate

question

88. An agricultural economist says that the correlation between corn prices and soybean prices is r=0.7. This means that

answer

when corn prices are above average, soybean prices also tend to be above average

question

89. A stratified random sample addresses the same issues as which of the following experimental designs

answer

a block design

question

90. A recent survey by a large-circulation Canadian magazine on the contribution of universities to the economy was circulated to 394 people who the magazine decided "are the most likely to know how important universities are to the Canadian economy." The main problem with using these results to draw conclusions about the general public's perception is

answer

lack of random selection

question

91. Let the random variable X represent the profit made on a randomly selected day by a certain store. Assume that X is Normal with mean $360 and standard deviation $50. What is P(X>$400)

answer

0.2119

question

92. Let the random variable X represent the amount of money Dan makes doing lawn care in a randomly selected week in the summer. Assume that X is Noraml with mean $240 and standard deviation $60. The probability is approximately 0.6 that, in a randomly selected week, Dan will make less than

answer

$255

question

93. At a school with 600 students, 25% of them walk to school each day. If we choose a random sample of 40 students from the school, is it appropriate to model the number of students in our sample who walk to school with a binomial distribution where n=40 and p=0.25

answer

Yes, because the sample size is less than 10% of the population size

question

94. A researcher reports that the participants in his study lost a mean of 10.4 pounds after two months on his new diet. A friend of yours comments that she tried the diet for two months and lost no weight, so clearly the report was a fraud. Which of the following statements is correct

answer

The report gives only the mean. This does not imply that all participants in the study lost 10.4 pounds or even lost weight. Your friend's experience does not necessarily contradict the study results.

question

95. For the histogram below, what is the proper ordering of the mean and median? Note that the graph is not numerically precise—only the relative points are important

answer

I is the mean and II is the median

question

96. In the setting of the previous problem, about what percent of the variation in the number of service calls is explained by the linear relation between number of service calls and number of machines

answer

74%

question

97. Use Scenario 3-15. Joseph is 22.5 months old. What is his predicted height

answer

79.11

question

98. The pie chart describes the distribution of state tree types for the 50 states in the United States. The category "Other" include all trees that are the state tree for two or fewer states. Which of the following conclusions can we draw from the chart

answer

There are 10 states that have designated pine as their state tree

question

99. A sample of student opinion at a Big Ten university selects an SRS of 200 of the 30,000 undergraduate students and a separate SRS of 100 of the 5,000 graduate students. This kind of sample is called a

answer

stratified random sample

question

100. In a large population of college students, 20% of the students have experienced feelings of math anxiety. If you take a random sample of 10 students from this population, the mean and standard deviation of the number of students in the sample who have experienced math anxiety is

answer

mean=2, s(x)=1.265

question

101. In order for the random variable X to have a geometric distribution, which of the following conditions must X satisfy? I. P<0.5 II. The number of trials is fixed III. Trials are independent IV. The probability of success has to be the same for each trial V. All outcomes in the sample space are equally likely

answer

III and IV

question

102. A new headache remedy was given to a group of 25 subjects who had headaches. Four hours after taking the new remedy, 20 of the subjects reported that their headaches had disappeared. From this information you can conclude

answer

nothing, because there is no control group for comparison

question

103. If we took an SRS of 1700 people from California (population 34 million) and a SRS of 1000 people from Detroit (population 1 million) which sampling distribution would have the smaller standard deviation

answer

California, because the sample size (1700) is larger than for Detroit (1000)

question

104. A friend has placed a large number of plastic disks in a hat and invited you to select one at random. He informs you that they have numbers of them, and that one of the following is the probability model for the number on the disk you have chosen. Which one is it

answer

the one where the probabilities add up to 1

question

105. Use Scenario 3-14. The least-squares regression line is the line that

answer

minimizes the sum of the squared residuals between the actual yield and the predicted yield

question

106. A fire department in a rural county reports that its response time to fires is approximately Normally distributed with a mean of 22 minutes and a standard deviation of 11.9 minutes. Approximately what proportion of their response times is over 30 minutes

answer

0.25

question

107. We wish to draw a sample of 5 without replacement from a population of 50 households. Suppose the households are numbered 01, 02,.....50, and suppose that the relevant line of the random number table is-11362 35692 96237 90842

answer

households 11,36, 23, 08, 42

AP Statistics
Dow Jones Industrial Average
Mean And Standard Deviation
Statistics

AP Statistics Ch 7 – Flashcards 35 terms
Sara Graham

35 terms
Preview

AP Statistics Ch 7 – Flashcards

question

A drastic drop of 500 points; after, a poll said 92% said they will be better in a year. What is 92%

answer

statistic

question

distribution of values taken by a statistic in all possible samples of the same size from the same population

answer

the sampling distribution of the statistic

question

if a statistic is used to estimate a parameter; the mean of its sampling distribution is equal to the true value of the parameter being estimated, the statistic is

answer

unbiased

question

you take a random sample of size 25 from a population with mean of 120 and standard deviation of 15. Your sample has a mean of 115 and a standard deviation of 13.8. Which has a mean of 120 and a standard deviation of 3?

answer

-the sampling distribution of the same mean 1) list what you are given -parameter: N=25, M=120, SD = 15 -Sample: M=115, SD = 13.8 -Statistic: M=120, SD = 3 2) Finding Sample Distribution: Parameter SD/sqroot(n) = 15/sqroot25 = 15/5 = 3

question

To calculate standard deviation of sample distribution (SD/sqroot(N)), which conditions must be met?

answer

-The sample size is less than 10% of population size (N)(.10) -does not matter what shape is

question

the central limit therorem

answer

regardless of shape of the populations distribution, the sampling distribution of the sample mean from sufficiently large samples will be approximately Normally distributed

question

A random sample of 1000 Americans said 62% were satisified with service provided by car dealer. A simple random sample of 1000 Canadians said 59% were. The sampling variability associated with these statistics is

answer

not exactly the same, but very close

question

Random sample of 16 students at school how many minutes they spend on English homework; u=45 minutes, SD = 15 minutes. Which of the following best describes what we know about the sampling distribution sample?

answer

1) List what we know: n=16, u = 45, SD = 15 2) We can infer that -Ux=45 -Ox= 15/sq(16) = 3.75 -Dont know shape

question

Olives are normally distributed with a mean of 7.7g and a SD of .2g. Represent the probability that the mean weight of a random sample of 3 olives from this population is greater than 8gm?

answer

Z> 8-7.7 / (.2/sq(3)) -put sample size under standard deviation

question

College freshman study mean of 7.2 hr and SD of 5.3 1) Can you calculate probability that a randomly chosen freshman studies more than 9 hours?

answer

no, we do not know the shape (shape = N)

question

College freshman study mean of 7.2 hr and SD of 5.3 What is the shape of the sampling distribution of mean x for samples of 55 randomly selected freshman?

answer

N= 55 55 is greater than 30 sample is approx normal

question

College freshman study mean of 7.2 hr and SD of 5.3 What are the mean and standard deviation for the mean number of hours x spent studying by an SRS of 55 freshman?

answer

Mx = 7.2 (same as sample) Ox = SD/sq(N) = 5.3/sq(55) = .715

question

College freshman study mean of 7.2 hr and SD of 5.3 Find the probability that the average number of hours spent studying by an SRS of 55 students is greater than 9 hours

answer

Ox= SD/sq(N) = 5.3/sq(55) = .715 Z > (9 - 7.2) / .715

question

In a game, a heads is to his advantage. You test a coin for fairness; 50 times and if probability is .50 it is fair -Assume it is .50. If p^ is the proportion of heads in 50 flips of the coin, what are the mean and SD of the sampling distribution of ^p?

answer

Up = P=.05 Op = sq ( (.5)(.5)/ 50 ) = .071

question

In a game, a heads is to his advantage. You test a coin for fairness; 50 times and if probability is .50 it is fair -Explain why you can use the formula for the standard deviation of ^p in this setting

answer

Possible coin flips is infinite; dont need to worry about 10% condition

question

In a game, a heads is to his advantage. You test a coin for fairness; 50 times and if probability is .50 it is fair -You flip the coin 50 times and get 30 heads. Will you insult your friend?

answer

30/50 = .6 = p^ P(P^ > .6) = Z > .6 - .5 / .071 P (Z > 141) = .793 8% of the time we get this many more heads

question

19% of cars made in 2007 were white. In a random sample of 100 cars parked in an airport, 22% of cars were right. Identify parameter and statistic.

answer

-19% is parameter -22% is statistic

question

Best statistic for estimating a parameter

answer

-low bias, low variability

question

a probability distribution that describes the relative likelihood of all possible values of a statistic

answer

a sample distribution

question

In a large population, mean IQ is 112 with SD 20. 200 adults are randomly selected for a market research campaign. Sampling distribution of sample mean IQ is

answer

-approx normal -mean 112 (given) -SD 1.414

question

If we take two samples from two different schools, what should the relative size of our samples be from each school if we want the two sampling distributions to have approx the same standard deviation?

answer

take the same size samples from each school

question

45% of SRS of 500 adults liked voucher idea -What is the mean of the sampling distribution of ^p, the proportion of adults in samples of 500 who favor vouchers?

answer

Mp^ = p = .45

question

45% of SRS of 500 adults liked voucher idea -What is the standard deviation of p^?

answer

Op^ = sq: (p)(1-p) / n -sq (.45)(.55) / 500 = .022

question

45% of SRS of 500 adults liked voucher idea -Check that you can use normal approximation for distribution of p^

answer

np > 10 and n(1-p) > O np = 500(.45) = 225 n(1-p) = 500(.55) = 275

question

45% of SRS of 500 adults liked voucher idea -What is the probability that more than half are in favor?

answer

Z > .5 - .45 / .22 (standard deviation of ^p: sq: (p)(1-p) / n -sq (.45)(.55) / 500 = .022

question

statistical inference

answer

use information form a sample to draw conclusions about a wider population -different samples yield different statistics: need to be able to describe sampling distribution of statistic values

question

parameter vs. statistics

answer

1) parameter: a number that describes some characteristic of the population (mean =M, SD= O, proportion= P) 2) Statistic: a number that describes some characteristic of a sample (mean = x-, SD = S, proportion = P^)

question

Sampling Distribution

answer

the distribution of values taken by the statistic in all possible samples of the same size from the same population

question

Describing Sampling Distribution

answer

-center: unbiased or biased (unbiased if mean of sampling distribution is equal to true value of parameter); bias if sample is not within range given (aim is off constantly; not in center) -spread: describes variability (determined by size); high variability if widely scattered (no consistent results); lower variability/small spread/large samples are better

question

sample distribution of p^

answer

-answers how good of an estimate statistic ^p is for parameter p

question

describing sample distribution of p^

answer

-shape: sometimes can be approximated by a normal curve; depends on sample size (n) and population proportion (p) -center: mean of the distribution is up = p -Spread: for a specific value of p, standard deviation Op gets smaller as n gets larger

question

mean and SD of sample distribution of p^

answer

(n = population, p = success, p^ is sample success) -mean of sample p^: up = p -SD of p^: Op = sq : (p)(1-p) / n -ONLY IF: 10% condition is met (n)(.10) > 10

question

sample distribution is approx normal if

answer

np >= 10 n(1-p) >= 10

question

sampling distribution of x- (sample mean)

answer

x- is the mean of SRS of size n drawn from large population with mean u and SD O -mean = ux= u -SD: Ox = O/sq(N) -ONLY IF 10% condition is met (n)(.10) > 10 -does not matter about size of population: if population distribution is normal, then so is the sampling distribution of X-, no matter what the sample size is

question

The Central Limit Theorem

answer

when n is large (>30) the sampling distribution of the sample mean X- is approximately normal (as sample size increases, distribution of sample means change shape: looks more like a Normal distribution and less like a population) -allows us to use Normal probability calculations to answer questions

AP Statistics
Mean And Standard Deviation
Standard Deviation Of The Mean
Statistics

105 questioned Stats Review – Flashcards 98 terms
Tara Rose

98 terms
Preview

105 questioned Stats Review – Flashcards

question

A set of Data has a mean that is much larger than the median.

answer

A stemplot of the data is skewed left

question

Interscholasic Sports, Intramural Sports, or No Sports

answer

Juniors have the highest percentage participation

question

AP Scores

answer

Median is 3

question

Birth Rate Median

answer

110

question

40 of the birth weights

answer

102

question

The number of children with birth weights between 102-122

answer

50%

question

Strongly Skewed to the left. Which combo of measure of center and spread?

answer

Median and IQR

question

Lobster fisherman

answer

14

question

Roughly locate the mean of a density curve by the eye because

answer

it is the point at which the curve would balance if made of solid material.

question

Roughly locate the median of a density curve by the eye because it is

answer

The point that divides the area under he curve into two separate parts

question

You are told your score on the exam is at the 85 percentile

answer

Your score was equal to or higher than approximately 85% of the people who took this exam.

question

Mr. William's calculus class

answer

79%

question

Pisaster arm length

answer

median - 15.2 IQR - 4.3

question

A Standard Score Describes

answer

How far a particular score is from the mean

question

Jack and Jill

answer

Jack - 1.07 Jill - 1.11 Jill Wins

question

A data set is Normally distributed with a mean of 25 and Standard Deviation of 8. If you calculate the standard score of every observation in this data set, what will the mean and Standard deviation of the resulting Scores be

answer

The mean of 0 Standard Deviation of 1

question

if 30 is added to every number on the list, what DOES NOT change?

answer

Standard Deviation

question

Standard deviation of salaries

answer

Increase by 3,000

question

The IQR of the salaries for the employees

answer

be unchanged

question

The z scores of the salaries for the employees will

answer

be unchanged

question

Birthweights at a local hospital have a norm dist. with a mean of 110

answer

.136

question

IQ's among undergraduates at mountain tech are...

answer

5

question

A company produces ceramic floor tiles

answer

.3085

question

the time to complete a standardized exam

answer

78.4

question

You are chatting with the principal of a local high school

answer

M = 550 SD = 75

question

Etymologist Heinz Kaefer

answer

310

question

Basketball - Total Assists

answer

The distribution is skewed

question

The response variable

answer

the volume of lumber

question

Which of the following Statements are supported by the scatterplot

answer

I II III

question

Two variables are said to be negatively associated if

answer

when above average values of 1 variable are associated with below average values of the corresponding Variable

question

Correlation coefficient measures

answer

the strength and direction of a linear relationship between two variables

question

Stopping distance vs. outside temperature... Correlation

answer

Approx. 0.6

question

Stopping distance vs. outside temp...if another data point

answer

Decrease since this new point is an outlier that does not follow the pattern in the date.

question

Intercept of Least Squares regression line is approx

answer

1.8

question

Based on the scatterplot the least squares line would predict that a car that emits 10 grams of CO per mile driven would emit approx. how many grams of nox

answer

1.1

question

The point indicated by the open circle

answer

has a negative

question

Least Squares in the term Least Squares Regression line refers to

answer

minimizing the squares of all the values of the response variable.

question

Which of the following statements are true about the least squares regression line

answer

I II III

question

Suppose we fit the LSR line to a set of data. If a plot of the residuals show a curve pattern

answer

the model is not appropriate

question

If removing an observation

answer

influential

question

Suppose a straight line is fit to data having

answer

Extrapolation.

question

The circled point on the scatter plot represents lima beans, which have 621 calories

answer

-4.18

question

Expected average error - LSRL Lima Bean

answer

3.37648

question

A study of child development measures the age

answer

the test scores gets down by 1.3 pts

question

equations - eggs

answer

Eggs = -142.74 + 39.25Length

question

Predicted y-values from the actual y-values

answer

25.55

question

You want to know the opinions of American school teachers... The population is

answer

2500 teachers chosen at random

question

A television station

answer

Voluntary Response Bias

question

a news release

answer

biased, overstating effect of diet

question

A simple random sample of size n is defined to be

answer

A sample of size n chosen in such a way that every set of n units has an equal chance to be the sample actually selected.

question

In an experiment an observed effect so large that it would rarely occur

answer

Statistically significant

question

Another correct label for 816 students

answer

01-815 ID

question

A public opinion poll in ohio

answer

Stratified random sample

question

Stratified random sample addresses the same issues as

answer

block design

question

In the late 1990's Scotland was considering independence from England

answer

the wording of the question

question

frequently, telephone poll takers call near dinner time

answer

nonresponse

question

Which of the following is not a major principle of good design for all experiments

answer

blocking

question

The essential difference between an experiment and an observational stud that

answer

an experiment imposes treatment on the subject, but an observational study does not

question

The reason blocking is sometimes used in experimentation is to

answer

reduce variability arrising from random assignment

question

Event A has probability of 0.4. Event B has a probability of 0.5. If A and B are disjoint then the probability that both events occur is

answer

question

The probability that the next five babies are girls is

answer

.03125

question

The probability that at least one of the next three babies is a boy

answer

.875

question

The events A = the nest two babies are boys, and B = the nest two babies are girls are

answer

disjoint

question

In a certain town...

answer

30%

question

Suppose A and B are independent events with P(A) = .2 and P(B) = .4

answer

.12

question

The probability your score 4 points both times is

answer

.0277

question

P(A u B) ------ Red and Green

answer

5/6

question

The event corresponding to the system failing during one period of operation is

answer

F&G

question

Event A occurs with a probability of .8. The conditional probability that event B occurs, given that A occurs is .5

answer

.4

question

Event A occurs with probability of 0.3 and event B occurs with probability of 0.4. If a and B are independent, we may conclude that

answer

all of the above

question

The card game Euchre uses a deck with 32 cards: Ace, King, Queen, Jack, 10, 9, 8, 7 of each suit.Suppose you choose one card at random from a well-shuffled Euchre deck. What is the probability that the card is a jack, given that you know it's a face card?

answer

1/4

question

Probability that the student has breakfast

answer

.5

question

Given that the student who ate breakfast is selected what is the probability he is male

answer

.64

question

Find P(B|F) and write in words what this expression represents

answer

The probability that the student ate breakfast given that she is female

question

P(AuB)

answer

Q + S + R

question

P(AnB)

answer

r/(q+r)

question

If a single student is selected at random and you know she has a dog. What is the probability that she also has a cat

answer

0.75

question

If two students are selected at random, what is the probability that neither of them has a dog or cat

answer

.548

question

Let X be the outcome of rolling a fair six-sided die. P(1<X<5)=

answer

.5

question

An expression the represents the probability of at least one tail is

answer

P(x<3)

question

The probability of at least one tail is

answer

.9375

question

In a particular game, a fair die is tossed. If the number of spots showing is either 4 or 5 you win $1, if the number of spots showing is 6 you win $4, and if the number of spots showing is 1, 2, or 3 you win nothing. Let Xbe the amount that you win. Use Scenario 6-2. Which of the following is the standard deviation of X?

answer

1.41

question

The probability that a random scratch card will pay off is

answer

.0601

question

The expected pay off per card

answer

.85

question

The mean number of customers that make a purchase during the first hour that the store is open

answer

3

question

The density curve for a continuous random variable X has which of the following properties

answer

All of the above

question

P(X>400$) is

answer

.2119

question

The probability is approximately 0.6 that on a randomly selected day the store will make less than which of the following amounts

answer

$372.60

question

Albert - What is the expected value of Z

answer

1.2

question

Alberts Game- Standard deviation and mean

answer

M = 1.6 SD = 1.2

question

What is the expected value of T

answer

40

question

Typically the formula 1.07

answer

m = 42.78 sd = 6.09

question

The distribution of X = the number of questions the student will correct is

answer

binomial with parameters n = 20 and p = 0.25.

question

Which of the following expresses the probability that the student gets no questions correct?

answer

.75^20

question

A college basketball player makes 5/6 of his free throws. Assuming free throw attempts are independent, the probability that he makes exactly three of his next four free throws is

answer

4 (1/6) ^ 1 (5/6) ^ 3

question

A college basketball player makes 80% of her free throws. Suppose this probability is the same for each free throw she attempts. The probability that she doesn't make a free throw until her fifth attempt this season is

answer

0.00128.

question

The Binomial expression

answer

.2731

question

A college basketball player makes 80% of her free throws. Suppose this probability is the same for each free throw she attempts. The expected number of free throws required until she makes her first free throw of the season is

answer

1.25

Elementary Statistics
High School Students
Probability And Statistics
Simple Random Sampling
Statistics
United States

Math 120 Practice Exam Chapter 1 – Flashcards 23 terms
Brooke Sharp

23 terms
Preview

Math 120 Practice Exam Chapter 1 – Flashcards

question

statistic

answer

In a poll of a 12,000 adults in a certain city, 12% said they left for work before 6 am

question

statistic

answer

in a national survey of high school students, 25% if respondent reported that someone had offered, sold, or given them an illegal drug on school property.

question

parameter

answer

Following the election, 18% of the governors of all 50 states were female

question

Qualitative

answer

address

question

Quantitative

answer

gallon of water in a swimming pool

question

quantitative

answer

Amount of money won in a lottery

question

discrete

answer

numbers of cars owned

question

continuous

answer

Amount of rainfall in a city in one year

question

discrete

answer

Number of days of rainfall in one year

question

What is the population in this study?

answer

The Gallup Organization contacts 2542 undergraduates who attend a college and live outside the U.S. and asks whether or not they had taken a course in conversational English during their studies. A. All undergraduates students who attend the college and live outside the U.S.

question

What is the sample in this study?

answer

The Gallup Organization contacts 2542 undergraduates who attend a college and live outside the U.S. and asks whether or not they had taken a course in conversational English during their studies. A. The 2542 undergraduates who attend college and live outside the U.S.

question

Experiment

answer

50 patients with colon cancer are divided into two groups. One group recieves an experimental drug to fight cancer, the other gets a placebo. After one year the spread of cancer is measured.

question

Observational study

answer

While shopping, 275 people are asked to perform a taste test in which they eat two placed, unmarked soups. They are asked which soup they prefer.

question

What is the responce variable?

answer

Researchers wanted to determine if there was an asscosiation between daily coffee consumption and the occurance of skin cancer. The researchers looked at 94,383 woman and asked them to report nonmelanoma skin cancer. After their analysis, the researchers, concluded that consumption of six or more cups caffinated per day was associated in nonmelnoma skin cancer. A. nonmelanoma skin cancer

question

What is explanatory variable in this study?

answer

Researchers wanted to determine if there was an asscosiation between daily coffee consumption and the occurance of skin cancer. The researchers looked at 94,383 woman and asked them to report nonmelanoma skin cancer. After their analysis, the researchers, concluded that consumption of six or more cups caffinated per day was associated in nonmelnoma skin cancer. A. daily coffee consumption

question

Can the researchers say that the consumption of six or more cups of caffinated coffee per day will cause a reduction in nonmelanoma skin cancer?

answer

Researchers wanted to determine if there was an asscosiation between daily coffee consumption and the occurance of skin cancer. The researchers looked at 94,383 woman and asked them to report nonmelanoma skin cancer. After their analysis, the researchers, concluded that consumption of six or more cups caffinated per day was associated in nonmelnoma skin cancer. A. No, this is an observational we cannot claim causation only association

question

Determine the sample of the 5 faculty members

answer

A small community college employs 58 full time faculty members. To gain faculty opinions about upcoming contract negotiations, the president of the faculty union wishes to obtain a simple random sample that will consist of 5 faculty measures. Using the table start with row 19,column A. 12, 39,29,9,58

question

Systematic Sampling

answer

To estimate the percentage of defects in the a recent manufacturing branch, a quality control manager at GE selects every 15th refrigerator that comes off the assembly linestarting with the second until she obtains a sample of 100 refridgerator.

question

Cluster

answer

To determine customer opinion of their safty features, Toyata randomly selcts 30 dealerships during a certain week and surveys all customers visiting the dealership.

question

Convinence

answer

A newspaper asks its readers to call in their opinion regarding the number of books they have read this month.

question

Stratified

answer

Thirty-five sophmores, 23 juniors and 38 seniors are randomly selected to participate in a study from 574 sophmores, 543 juniors, and 542 seniors.

question

simple random

answer

Ford wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 40 customers and asks them about their level of satisfaction with the company.

question

Sampling Bias

answer

The owner of a shopping mall wishes to expand

Area
Comparison
Statistics

stats chapter 5 – Flashcards 105 terms
Ben Powell

105 terms
Preview

stats chapter 5 – Flashcards

question

If a student is selected at random, what is the probability that this student spends more than $425 on books?

answer

This cannot be determined from the information given.

question

What is the standard deviation of the sampling distribution of the sample mean score for a random sample of 36 students?

answer

1.0

question

A sample of size n is selected at random from a population that has mean μ and standard deviation σ. The sample mean will be determined from the observations in the sample. Which of the following statements about the sample mean, , is (are) TRUE?

answer

All of the above are true

question

Which figure below is most likely a result of sampling the most observations to obtain the distribution of ?

answer

c.

question

What is the sampling distribution of the sample mean score for a random sample of 36 students?

answer

Exactly Normal.

question

The distribution of the sample mean has a standard deviation that is ________ the standard deviation of the distribution of the population from which it was sampled.

answer

smaller than

question

Sodas in a can are supposed to contain an average of 12 ounces. This particular brand has a standard deviation of 0.1 ounces, with an average of 12.1 ounces. If the can's contents follow a Normal distribution, what is the probability that the mean contents of a six-pack are less than 12 ounces?

answer

0.007

question

If the population variable is known to be Normally distributed and the sample size used is to be n = 16, what is the probability that the sample mean will be between 48.35 and 55.74, i.e., P(48.35 ≤ ≤ 55.74)?

answer

0.607

question

Which of the following statements is not true?

answer

A histogram of T-cell velocities would be more Normal if the researchers had collected more data

question

The probability that the average age of the 400 trees is more than 60.1 years is

answer

0.1817

question

The lengths of individual fish in a pond have an approximate Normal distribution with a mean of 18.6 cm and a standard deviation of 6.0 cm. A sample of 36 fish is taken. What is the mean of the sampling distribution of the sample mean for the 36 fish?

answer

18.6 cm

question

The variability of a statistic is described by

answer

the spread of its sampling distribution.

question

Cats live for 14 years on average, with a standard deviation of 2 years. A simple random sample of 78 recently deceased cats is selected, and the sample mean age at death of these cats is computed. We know the random variable has an approximately Normal distribution because of

answer

the central limit theorem

question

A quality control manager initially plans to take a simple random sample of size n from the production line. If he were to double his sample size (to 2n), by what factor would the standard deviation of the sampling distribution of change?

answer

1/ radical 2

question

Ten medium oranges will be randomly selected from a package. What is the sampling distribution of the number of oranges in the sample that weigh more than 14 oz?

answer

B(10, 0.5)

question

What is the probability that the average time 100 random students on campus will spend between 1 hour and 5 hours on the internet?

answer

0.5

question

What proportion of tanks will hold between 14.75 and 15.10 gallons of gas?

answer

0.6997

question

What is the variance, , of the sampling distribution of the sample mean, ?

answer

None of the above

question

If the quality control manager takes a simple random sample of ten chocolate bars from the production line, what is the probability that the sample mean weight of the 10 sampled chocolate bars will be less than 8.0 oz?

answer

0.00078

question

What is the probability that the average time 100 random students on campus will spend less than 1 hour on the internet?

answer

question

If a simple random sample of four tanks is selected, and their capacities can be considered independent, what is the probability that all four will hold between 14.75 and 15.10 gallons of gas?

answer

0.2397

question

We know the random variable has an approximately Normal distribution because of

answer

the central limit theorem.

question

If you take a random sample of 25 vitamin drops, what is, approximately, the probability that the average vitamin content is less than 59.9 mg?

answer

0.16

question

The fact that the sample mean doesn't tend to over- or under-estimate the population mean makes the sample mean

answer

unbiased.

question

If the survey had interviewed only 1000 people, which of the following would be true?

answer

None of the above

question

A statistic here is

answer

the mean calculated from the 400 trees.

question

In order to reduce the standard deviation from the sampling distribution of the sample mean, you should`

answer

take larger samples

question

In the construction industry, compressive strength of concrete is a crucial characteristic. Suppose for a particular residential construction job the concrete tested after 3 days should have a mean compression strength of μ = 3000 psi with a standard deviation of σ = 50 psi. It is known that compressive strength of concrete is Normally distributed. On a construction site, a sample of n = 5 specimens is selected and tested after 3 days. If the concrete has the desired characteristics, what is the probability that the sample mean will be larger than 3060 psi?

answer

0.004

question

The scores of individual students on the American College Testing (ACT) Program composite college entrance examination have a normal distribution with mean 18.6 and standard deviation 6.0. At Northside High, 36 seniors take the test. If the scores at this school have the same distribution as national scores, the sampling distribution of the average (sample mean) score for the 36 students is

answer

exactly Normal.

question

Based on the central limit theorem, the sampling distribution of the sample mean becomes more normal as the sample siz

answer

increases

question

What is the probability that the average time 100 random students on campus will spend more than 5 hours on the internet?

answer

0.5

question

The probability that the sample mean IQ is greater than 120 is

answer

0.0790

question

If you take a random sample of 25 adult men with liver cirrhosis, what is the probability that their average total body protein is between 9.75 and 9.85 kg?

answer

0.9876

question

If you take a random sample of 25 vitamin drops, what is, approximately, the probability that the average vitamin content is between 60.25 and 60.75 mg?

answer

0.01

question

Considering a sample of 3800 people a large sample, which of the following is true?

answer

By the central limit theorem, the average amount of gasoline from repeated samples of size 3800 is approximately Normally distributed

question

What is the probability that the mean pH measurement of these 4 specimens is greater than 8.2?

answer

0.0912

question

Suppose a simple random sample of 100 observations is to be selected from the population and the sample average, , calculated. Which of the following statements about the distribution of is (are) FALSE?

answer

Because the distribution shown in the histogram above is clearly skewed to the right, the shape of the distribution of will also show skewness to the right.

question

A travel agent randomly selects prices of nonsmoking rooms with a king-size bed from 15 hotels in the area. What is the probability that their average cost will be more than $150?

answer

0.0077

question

From the central limit theorem, we know that if we draw a SRS from any population the sampling distribution of the sample mean will be EXACTLY Normal.

answer

false

question

If a simple random sample of 100 undergraduate students is selected, what is the probability that these students spend, on average, more than $425 on books?

answer

0.00089

question

The central limit theorem says that the sampling distribution of the sample mean is approximately _______ for large n.

answer

N(u0/radical) the long answer

question

he quality control specialist will take a simple random sample of 2000 batteries produced at this plant over the next four days. These batteries will be put into a variety of moderately sized appliances and the average of all failure times will be computed. Which of the following probability distributions is most appropriate to model the average time until failure of these 2000 batteries?

answer

The Normal distribution

question

How big must the sample size n be so that the standard deviation of the sample mean, , is equal to 1.4, i.e., = 1.4?

answer

n = 115

question

Use the 68-95-99.7 rule to answer this question. What is the range of average pH measurements that make up roughly the middle 95% of the sampling distribution for random samples of 4 specimens?

answer

7.7 to 8.3

question

A statistic is said to be unbiased if

answer

the mean of its sampling distribution is equal to the true value of the parameter being estimated

question

Suppose that scores on the Math SAT exam follow a Normal distribution with mean 500 and standard deviation 100. Two students that have taken the exam are selected at random. What is the probability that the sum of their scores exceeds 1200?

answer

0.0793

question

Incomes in a certain town are strongly-right skewed with mean $36000 and standard deviation $7000. A random sample of 10 households is taken. What is the probability the average of the sample is more than $38000?

answer

Cannot say

question

Sample means are more skewed than individual observations.

answer

false

question

Based on the central limit theorem, the sampling distribution of the sample mean becomes more normal as the sample size

answer

increases

question

The quality control manager plans to take a simple random sample of size n from the production line. How big should n be so that the sampling distribution of has standard deviation 0.01 oz?

answer

100

question

Suppose a simple random sample is selected from a population with mean μ and variance σ2. The central limit theorem tells us that

answer

if the sample size is sufficiently large, the distribution of will be approximately Normal with mean μ and standard deviation,

question

The scores of individual students on the American College Testing (ACT) Program College Entrance Exam have a normal distribution with mean 18.6 and standard deviation 6.0. At Westside High, 400 students take the test. Assume their scores are all independent. If the scores at this school have the same distribution as nationally, the probability that the average of the scores of all 400 students exceeds 19.0 is

answer

smaller than the probability that a single student has a score exceeding 19.0

question

Central limit theorem only applies when sampling from Normal populations.

answer

false

question

The distribution of the lengths of all the fish in the lake is the

answer

population distribution of fish lengths

question

If you take a random sample of 25 healthy adult men, what is the probability that their average total body protein is between 12.25 and 12.35 kg?

answer

0.9876

question

Sale of eggs that are contaminated with salmonella can cause food poisoning among consumers. A large egg producer takes an SRS of 200 eggs from all the eggs shipped in one day. The laboratory reports that 11 of these eggs had salmonella contamination. Unknown to the producer, 0.2% (two-tenths of one percent) of all eggs shipped had salmonella. In this situation

answer

0.2% is a parameter and 11 is a statistic.

question

A parameter in this situation is

answer

the true mean amount of gasoline used the previous week by all people age 18 and older

question

The manufacturer of this gasoline tank considers the largest 2% of these tanks too large to put on the market. How large does a tank have to be, to be considered too large?

answer

15.31 gallons

question

A machine fills cans of soda which are labeled "12 ounces" according to a Normal distribution with mean 12.1 ounces and standard deviation 0.1 ounces. If I buy a 12-pack of the soda, what is the chance the average contents of the cans will be less than advertised?

answer

0.0003

question

For the passengers in the SRS, what is the approximate probability that the mean length of time for them to get through security will be less than 18 minutes?

answer

0.031

question

What is the probability that a carton of a dozen eggs weighs more than 13 oz?

answer

0.0019

question

A length of chain is to be constructed by placing 36 component links end-to-end. The length of a link produced by a production process is known to be a random variable with mean μ = 2.5 cm with a standard deviation σ = 0.2 cm. The 36 links are chosen at random from this process to produce the chain. The mean and standard deviation of the length of chain are, respectively

answer

90 cm, 1.2 cm

question

The distribution of the sample mean IQ is

answer

approximately Normal, mean 118, standard deviation 1.414

question

The lengths of individual fish in a pond have an approximate Normal distribution with a mean of 18.6 cm and a standard deviation of 6.0 cm. A sample of 36 fish is taken. What is the standard deviation of the sampling distribution of the sample mean for the 36 fish?

answer

1.0 cm

question

If you take a random sample of 16 healthy adult men, what is the probability that their average total body protein is between 12.25 and 12.35 kg?

answer

0.9545

question

What percentage of nonsmoking rooms with a king-size bed cost more than $150?

answer

26.60%

question

Incomes in a certain town are strongly right-skewed with mean $36000 and standard deviation $7000. A random sample of 75 households is taken. What is the probability the sample mean is greater than $37000?

answer

0.1075

question

The central limit theorem says that, when a simple random sample of size n is drawn from any population with mean μ and standard deviation σ, then when n is sufficiently large

answer

the distribution of the sample mean is approximately Normal.

question

In a simple random sample of 100 undergraduate students, what is the expected value of the sample mean amount of money spent on books?

answer

$400

question

What is the probability that will be less than 1190?

answer

0.1335

question

What is the mean of the sampling distribution of the sample mean score for a random sample of 36 students?

answer

18.6

question

A statistic in this situation is

answer

11.75 gallons

question

The central limit theorem does not apply to discrete random variables.

answer

false

question

The sampling distribution of a statistic is

answer

the distribution of values taken by a statistic in all possible samples of the same size from the same population

question

The scores of individual students on the American College Testing (ACT) Program composite college entrance examination have a Normal distribution with mean that varies slightly from year to year and standard deviation 6.0. You plan to take an SRS of size n of the students who took the ACT exam this year and compute the mean score of the students in your sample. You will use this to estimate the mean score of all students this year. In order for the standard deviation of to be no more than 0.1, how large should n be?

answer

at least 3600

question

A market research company wishes to find out whether the population of students at a university prefers Brand A or Brand B of instant coffee. A random sample of 100 students is selected, and each one is asked to try Brand A and then Brand B (in random order). They then indicate which brand they prefer, and 65 students preferred Brand B. Which is the parameter of interest?

answer

question

Let X be a binomial random variable with distribution B(10, 0.6). What is the probability that X equals 8?

answer

45(0.6)8(0.4)2

question

For which of the following does the random variable X have a binomial distribution?

answer

X is the number of people in a random sample of size 50 from a large population that have type-AB blood.

question

A company is being criticized because only 3 of 16 people in executive-level positions are female. The company claims that although the number is lower than it might wish, it is not surprising given the fact that only 40% of their employees are women. Suppose we can consider the 16 people in executive-level positions as a simple random sample of all employees. What is the probability of observing 3 or less women in the group of 16 executives?

answer

(20/6)(0.42)6(0.58)14

question

There are twenty multiple-choice questions on an exam, each having responses a, b, c, or d. Each question is worth 5 points and only one response per question is correct. Suppose a student guesses the answer to each question, and her guesses from question to question are independent. On average, this strategy will result in a mean score of

answer

25

question

It has been asserted that 15% of all people are left-handed. In a random group of 10 people, what is the chance that not all of them are right-handed

answer

80.3%

question

The probability of success for binomial distribution must remain the same for each observation.

answer

false

question

What is the probability that all students in a simple random sample of 15 students own a cell phone?

answer

0.206

question

If the true proportion of clients who are very satisfied with the Big Smiles Portrait Studio and would therefore recommend the studio to a friend is 82%, what is the probability that more than 60 clients in the sample would answer Yes on the survey question?

answer

0.0054

question

One of the requirements for the binomial distribution is that the observations are all _____.

answer

independent

question

Over the course of the season, he will attempt 100 free throws. Assuming free-throw attempts are independent, what is the probability that he makes at least 90 free throws?

answer

.0057

question

Mr. Aaron is about to interview four candidates for a certain job. He hopes all the candidates turn off their cell phones, because he does not like to be interrupted by a ringing cell phone. If there is only one candidate whose cell phone rings during the interview, Mr. Aaron will immediately not hire this candidate. If there is only one candidate whose cell phone does not ring during the interview, he will immediately hire this candidate. Suppose all four candidates own cell phones and none turn his/her cell phone off. Each of the candidates will have a 50% chance of being called during their interview. What is the probability that Mr. Aaron will find himself in either one of the two above-described situations: to immediately not hire one candidate because his/her cell phone rang during the interview or to immediately hire one candidate because his/her cell phone was the only one that did not ring during the interview?

answer

0.50

question

A high school has 1000 students. As a school project, the school conducts a mock lottery. Each student in the school is asked to select an integer between 1 and 1000, independently of the choices of the other students. Each student gives their selection, with their name, to the school principal. The school principal uses a random number generator to select an integer between 1 and 1000 and any student that picked this number is declared a winner. What is the probability that no student wins?

answer

(0.999)1000

question

What is the percentage of young adults who do not own a landline?

answer

75%

question

A set of ten cards consists of five red cards and five black cards. The cards are shuffled thoroughly and I am given the first four cards. I count the number of red cards X in these four cards. The random variable X has which of the following probability distributions?

answer

Neither choice is correct.

question

The binomial coefficient, written , gives what information?

answer

the number of ways in which one can obtain k successes in n trials

question

A national poll of 600 men announced that the proportion in the survey who claimed to help their wives at home was 85%. If we took a larger poll of 1200 men, about how many would we expect to say that they help their wives at home, based on the first survey?

answer

1020

question

Six of these cards will be selected at random. Let X = the number of red cards observed in the set of six selected cards. Which of the following probability distributions is appropriate for modeling the random variable X?

answer

none of the above

question

Big Smiles has studios all across the country. Each studio surveys 65 of their clients and records the number of surveyed clients that respond Yes. If a studio scores in the top 6% of the distribution for the number of clients who answer Yes, then the studio will receive an award. Approximately how many clients had to answer Yes on the survey question before the studio will win an award?

answer

58

question

What is the probability that everyone in a simple random sample of 100 young adults owns a landline?

answer

Less than .001

question

Over the course of the season, he will attempt 100 free throws. Assuming free-throw attempts are independent, what is the probability that the number of free throws he makes exceeds 80?

answer

.4602

question

At the end of a game, his team is losing by two points. He is fouled attempting a three-point shot and is awarded three free throws. Assuming each free throw is independent, what is the probability that he makes at least two of the free throws?

answer

0.896

question

For each of the following scenarios, select if the binomial distribution is the appropriate distribution for the random variable X.

answer

Five random digits are to be randomly selected from your table of random digits (Table B). Let X = the number of sevens in this set of 5 random digits.

question

Suppose we roll a fair six-sided die ten times. What is the probability that even numbers occur exactly the same number of times as do odd numbers on the ten rolls?

answer

0.2461

question

What is the standard deviation of the number of students who own a cell phone in a simple random sample of 15 students?

answer

1.16

question

When a particular penny is held on its edge and spun, the probability that heads are face up when the coin comes to rest is 4/9. If the coin is spun 4 times, the probability that the coin will come up heads exactly twice is (assume trials are independent)

answer

0.366.

question

Which of the following might be reasonably modeled by the binomial distribution?

answer

Neither choice is correct.

question

What is the probability that no one in a simple random sample of 100 young adults owns a landline?

answer

question

The binomial distribution is a continuous distribution.

answer

false

question

If the coin is tossed six times, what is the probability that less than ⅓ of the tosses are heads?

answer

0.109

AP Statistics
Probability And Statistics
Statistics

Stat exam 1 terms. – Flashcards 34 terms
Sean Mitchell

34 terms
Preview

Stat exam 1 terms. – Flashcards

question

Population

answer

The set of all elements of interest in a particular study. (2) The collection of all elements of interest.

question

Parameter

answer

A numerical characteristic of a population, such as population mean μ, a population standard deviation σ, a population proportion p, and so on.

question

Sample

answer

A subset of the population.

question

Statistic

answer

A numerical characteristic of a Sample.

question

Sample Size

answer

The number of units in your sample

question

Census

answer

A survey to collect data on the entire population.

question

Pie Chart

answer

A graphical device for presenting data summaries based on subdivision of a circle into sectors that correspond to the relative frequency for each class.

question

Bar Chart

answer

A graphical device for depicting qualitative data that have been summarized in a frequency, relative frequency, or percent frequency distribution.

question

Frequency Distribution

answer

A tabular summary of data showing the number (frequency) of data values in each of several nonoverlapping classes.

question

Histogram

answer

A graphical presentation of a frequency distribution, relative frequency distribution, or percent frequency distribution of quantitative data constructed by placing the class intervals on the horizontal axis and the frequencies, relative frequencies, or percent frequencies on the vertical axis.

question

Scatter Diagram

answer

A graphical presentation of the relationship between two quantitative variables. One variable is shown on the horizontal axis and the other variable is shown on the vertical axis. (2) A graph of bivariate data in which the independent variable is on the horizontal axis and the dependent variable is on the vertical axis.

question

Time Series Plot

answer

A graphical presentation of the relationship between time and the time series variable. Time is shown on the horizontal axis and the time series values are shown on the vertical axis.

question

Mean

answer

A measure of central location computed by summing the data values and dividing by the number of observations.

question

Mode

answer

A measure of location, defined as the value that occurs with greatest frequency.

question

Median

answer

A measure of central location provided by the value in the middle when the data are arranged in ascending order.

question

Range

answer

A measure of variability, defined to be the largest value minus the smallest value.

question

Standard Deviation

answer

1) A measure of variability computed by taking the positive square root of the variance. (2) The positive square root of the variance.

question

Interquartile Range

answer

A measure of variability, defined to be the difference between the third and first quartiles.

question

Variance

answer

(1) A measure of variability based on the squared deviations of the data values about the mean. (2) A measure of the variability, or dispersion, of a random variable.

question

Quartile

answer

The 25th, 50th, and 75th percentiles, referred to as the first quartile, the second quartile (median), and third quartile, respectively. The quartiles can be used to divide a data set into four parts, with each part containing approximately 25% of the data.

question

Box Plot

answer

A graphical summary of data based on a five-number summary.

question

Correlation coefficient

answer

(1) A measure of linear association between two variables that takes on values between -1 and +1. Values near +1 indicate a strong positive linear relationship; values near -1 indicate a strong negative linear relationship; and values near zero indicate the lack of a linear relationship. (2) A measure of the strength of the linear relationship between two variables.

question

Data Types

answer

...

question

Qualitative

answer

Non-numeric values that indicate something about a set data

question

Quantitative

answer

Numeric values that indicate how much or how many of something. Quantitative data are obtained using either the interval or ratio scale of measurement.

question

Nominal

answer

The scale of measurement for a variable when the data are labels or names used to identify an attribute of an element. Nominal data may be nonnumeric or numeric.

question

Ordinal

answer

The scale of measurement for a variable if the data exhibit the properties of nominal data and the order or rank of the data is meaningful. Ordinal data may be nonnumeric or numeric.

question

Discrete

answer

random variable that may assume either a finite number of values or an infinite sequence of values.

question

Continuous

answer

A random variable that may assume any numerical value in an interval or collection of intervals.

question

Cross-sectional

answer

Data collected at the same or approximately the same point in time.

question

Empirical Rule

answer

A rule that can be used to compute the percentage of data values that must be within one, two, and three standard deviations of the mean for data that exhibit a bell-shaped distribution.

question

Chebyshev's rule

answer

A theorem that can be used to make statements about the proportion of data values that must be within a specified number of standard deviations of the mean.

question

z-score

answer

A value computed by dividing the deviation about the mean (xi -) by the standard deviation s. A z-score is referred to as a standardized value and denotes the number of standard deviations xi is from the mean.

question

Percentile

answer

A value such that at least p percent of the observations are less than or equal to this value and at least (100 - p) percent of the observations are greater than or equal to this value. The 50th percentile is the median.

Bell Shaped Distribution
Computer Graphics
Discrete Or Continuous Data Set
Statistics

Statistics Study Guide – Flashcards 97 terms
Lewis Gardner

97 terms
Preview

Statistics Study Guide – Flashcards

question

Descriptive statistics

answer

A branch of statistics that uses numerical and graphical methods to look for patterns in a dataset and to present that information in a convenient form, but does not use analysis

question

Inferential statistics

answer

A branch of statistics that uses sample data to make estimates, predictions, and decisions about a population

question

Population

answer

A collection of individuals or objects that is under study

question

Sample

answer

A subset of the population

question

Variable

answer

A characteristic of interest about each individual element of a population or sample

question

Data

answer

Numbers or information with a context

question

Quantitative data

answer

Variables that can assume numerical values (in the true sense)

question

Qualitative data

answer

Variables that are not numerical (in the true sense) but are categorized into various groups

question

Simple random sample

answer

A sample in which each element in the population has an equal chance of being selected

question

Systematic sample

answer

A sample in which the first element is picked at random, and then every kth element is picked

question

Stratefied random sample

answer

A sample obtained by stratifying the sampling frame and then selecting a fixed number of elements from each stratum by simple random sampling

question

Cluster sample

answer

A sample obtained by sampling some of, but not all of, the possible subdivisions within the population

question

Frequency distribution

answer

A tabular summary of data showing different classes and the frequency of items in each of several non-overlapping classes

question

Relative frequency distribution

answer

A tabular summary of data showing both the frequency and the relative frequency of items in each class

question

Relative frequency

answer

The proportion of the total number of observations belonging to the class

question

Bar chart

answer

A graphical summary of data that uses bars of fixed width and varying height to show the frequency or relative frequency of items in each class

question

Pie chart

answer

A graphical summary of data that uses a circle partitioned into sectors to show the relative frequency of items in each class

question

Distribution

answer

How the observations are spread over the range of the data

question

Positive distribution

answer

Skewed to the right; a distribution with a high frequency of observations in the lower end of the range

question

Symmetric distribution

answer

A mound- or bell-shaped distribution with a high frequency of observations in the middle of the range

question

Negative distribution

answer

Skewed to the left; a distribution with a high frequency of observations in the high end of the range

question

Stem and leaf plot

answer

A summary of data that divides each observation into two parts, with the leaves grouped on a stem

question

Leaf

answer

The right-most digit of each observation (in a stem and leaf plot)

question

Stem

answer

The digits of each observation, excluding the leaf (in a stem and leaf plot)

question

Leaf unit

answer

The unit used to separate the leaf from a stem in a stem and leaf plot, assumed to be 1

question

Split stem plot

answer

A stem and leaf plot in which some stems are split into two parts to reduce the size of the plot

question

Histogram

answer

A graphical representation of frequency distribution in which observations are divided into classes

question

Center

answer

Measure of central tendency

question

Variability

answer

Spread of the data

question

Mean

answer

The average of a group of numbers

question

Sample-mean

answer

x-bar; The mean of a sample data

question

Median

answer

The middle-most observation

question

Mode

answer

The most frequent observation

question

Range

answer

The difference between the minimum and maximum observations

question

Variance

answer

The average squared distance between all the observations and the mean

question

Formula for population variance

answer

δ²=∑(X-µ)²/N

question

Formula for sample variance

answer

s²=∑(xi-x-bar)²/n-1

question

Standard deviation

answer

Square root of variance, or average between a typical observation and the mean of a dataset

question

Formula for population standard deviation

answer

δ=√∑(X-µ)²/N

question

Formula for sample standard deviation

answer

s=√∑(xi-x-bar)²/n-1

question

The empirical rule

answer

For data with a bell-shaped distribution, approximately 68% of the observations will be within one standard deviation of the mean, approximately 95% of the observations will be within two standard deviations of the mean, and approximately 99.7% of the observations will be within three standard deviations of the mean

question

Chebyshev's rule

answer

For any number k>1, at least (1-1/k²) fraction of the data will lie within k standard deviations of the mean

question

Z score

answer

Measures the relative position of an observation compared to the mean, expressed in terms of standard deviation

question

Formula for sample z-score

answer

z=x-xbar/s

question

Formula for population z-score

answer

z=x-µ/δ

question

Outlier

answer

An extreme observation that does not match the general pattern of a dataset

question

Percentile ranking

answer

A way to express where an observation falls in a dataset using percentiles

question

Quartile

answer

One of three numbers which partition a dataset into four parts

question

Interquartile range

answer

Another measure of spread, which gives the middle 50% of a dataset

question

Box plot

answer

A graphical representation of the distribution using five numbers: minimum, lower quartile, median, upper quartile, maximum

question

Probability

answer

Study of randomness and uncertainty; numerical measure of chance

question

Empirical probability

answer

P(Event) = Relative frequency of the event = Number of occurrences of an event/Number of times experiment is repeated

question

Law of Large Numbers

answer

When an experiment is repeated many times, then the relative frequency of a particular outcome approaches the actual probability of that particular outcome

question

Subjective probability

answer

A probability assigned based on the subjective judgment of an individual

question

Theoretical probability

answer

A probability in which basic outcomes of the process are defined, probabilities are assigned to the basic outcomes and probabilities of compound events are computed

question

Experiment

answer

A process that yields a single outcome that cannot be predicted with certainty

question

Sample point

answer

Basic outcome of an experiment

question

Sample space

answer

Set of all possible outcomes of an experiment, denoted by S

question

Event

answer

Any subset of the sample space

question

Example of a sample space

answer

S = {HH, HT, TH, TT}

question

Examples of sample points

answer

HH, HT, TH, TT

question

Basic counting principle

answer

In an experiment done in two independent stages, where Stage I has m possible outcomes and Stage II has n possible outcomes, the experiment can be performed in (m)(n) ways

question

Factorial

answer

n! = (n)(n-1)(n-2)...3.2.1

question

Permutation

answer

Ordered arrangement

question

Compound event

answer

A composition of 2 or more events, can be the result of a union or intersection of events

question

Venn diagram

answer

Pictorial diagram in which the sample space is represented by a rectangle with sample points represented by solid dots inside the rectangle and events by circles within the rectangle

question

Union

answer

The entire Venn diagram, including both circles and the intersection

question

Intersection

answer

The part of a Venn diagram where the circles overlap

question

Complementary event

answer

All sample points that do not belong to the event

question

Mutually exclusive events

answer

Events that share no sample points

question

Additive rule of probability

answer

For any two events A and B, P(AUB) = P(A) + P(B) - P(AB)

question

Conditional probability

answer

Probabilities of events change when additional information is provided, in particular, if another related event is known to have occurred

question

Multiplicative rule

answer

P(AB)=P(A)P(B|A)=P(B)P(A|B)

question

Independence

answer

Events that do not depend on the outcome of another event

question

Random variable

answer

A variable that assigns a unique value to each outcome of the Sample space, S

question

Discrete random variable

answer

A random variable that takes either finitely many values or a countably infinite set of values

question

Countable set

answer

A set in one to one correspondence with integers

question

Continuous random variable

answer

A variable in which the set of possible values consists of one or more intervals on the number line

question

Probability distribution

answer

Specification of the possible values and probability associated with each possible value of the discrete random variable

question

Expected value (mean)

answer

The center of the distribution of a random variable

question

Formula for expected value

answer

µ=E(X)=∑x p(x)=x₁*p(x₁)+x₂*p(x₂)...

question

Formula for variance of a discrete random variable

answer

δ²=E(X-µ)²=∑(x-µ)²p(x)=∑x²p(x)-µ²

question

Bernoulli

answer

A random variable that can assume only two possible values: 1 (success) and 0 (failure)

question

Binomial experiment

answer

An experiment in which identical trials are repeated and we are interested in the number of certain outcomes

question

Binomial random variable

answer

The number of successes in n trials

question

Finite interval

answer

An interval of the form (a,b) or [a,b]

question

Semifinite interval

answer

An interval of the form [0,∞)

question

Real line

answer

An interval of the form (-∞,∞)

question

Area under the curve

answer

How to determine probability using a probability histogram

question

Probability density function (PDF)

answer

Height of the curve at x

question

Normal distribution

answer

A distribution that models population distributions with a symmetric mound shaped distribution

question

Parameter

answer

Numerical descriptive measure of the population

question

Sample statistic

answer

Numerical descriptive measure of the sample

question

Central limit theorem

answer

If the sample size n is large then the sampling distribution x-bar is approximately normal with mean µ and variance δ/√n

question

Target parameter

answer

The unknown population parameter that we are interested in estimating.

question

Point estimator

answer

A rule or formula that tells us how to use the sample data to calculate a single number that can be used as an estimate of the target parameter (example: sample mean).

question

Interval estimator (confidence interval)

answer

A formula that tells us how to use the sample data to calculate an interval that estimates the target parameter.

AP Statistics
Data
Elementary Statistics
Statistics

Statistics Test 1 (1-4) – Flashcards 81 terms
Jaxon Craft

81 terms
Preview

Statistics Test 1 (1-4) – Flashcards

question

characteristics of people or things

answer

In statistics variables are

question

population

answer

In statistics, the data we work with is just one part of a bigger picture called the

question

How where the variables measured? What variables were measured? Who collected the data?

answer

What are some things that should be asked when developing an understanding of data?

question

Numerical and Categorical

answer

What are two basic types of variables in statistics?

question

qualitative

answer

Categorical values are also referred to as ____ variables.

question

quantitative

answer

Numerical values are also referred to as ____ variables.

question

Variation and data

answer

The study of statistics rest on what two major concepts?

question

context

answer

Data are more than just numbers, because data have _____

question

Variation

answer

The circles shown are similar, but not exactly the same. This is an example of?

question

frequency

answer

The number of times a value is observed in a data set is called a ___

question

They take into account possible differences among the sizes of the groups.

answer

Why are percentages or rates often better than counts for making comparisons?

question

The response variable

answer

The outcome variable in a question about causality is also referred to as what?

question

The Control Group

answer

In an experiment studying the association between a treatment variable and an outcome variable, the group of people who do NOT receive the treatment are called what?

question

Controlled Experiments

answer

Of the following, which is the only method of data collection suitable for making conclusions about causal relationships? Observational Studies Anecdotes Controlled Experiments All three are suitable

question

A confounding variable

answer

A differences between two groups in an observational study that can explain why the outcomes were very different between the groups is called what?

question

To make the groups as similar as possible, minimizing bias.

answer

Why is random assignment used to assign people to treatment groups and control groups in a controlled experiment?

question

Equal sample sizes for control and treatment group

answer

Which of the following is NOT one of the criteria for the "gold standard" for experiments? Large Sample Size Random assignment of subjects to treatment or control groups Double-blinding Equal sample sizes for control and treatment group

question

distribution of a sample

answer

The ____ organizes data by recording all the values observed in a sample as well as how many times each values was observed.

question

See the data and summarize it

answer

What two-step process is used to examine distributions?

question

bins

answer

In a histogram, observations are grouped into intervals called _____.

question

changes the shape of the histogram

answer

Changing the width of bins in a histogram ______

question

proportion

answer

"Relative frequency" is the same as?

question

When technology is not availiable and the data set is not large

answer

A stemplot is often useful when?

question

How many numbers are in the data set

answer

When examining the shape of a distribution of numerical data, which of the following is NOT one of the three basic characteristics of a distribution's shape? Whether the distribution is symmetric of skewed How many numbers are in the data set How many mounds appear Whether any unusually large or small values are present

question

Two very different groups have been combined into a single collection

answer

The existence of multiple mounds in a distribution is sometimes a sign of what?

question

Outliers

answer

Values so large or so small that they do not fit into the pattern of the distribution are called what?

question

Bar graph and pie chart

answer

Two commonly used graphs to display the distribution of a sample of categorical data are?

question

A bar chart is used for numerical variables while a histogram is used for categorical variables.

answer

What is the main difference between a bar chart and a histogram?

question

They are not commonly used by statisticians or in scientific settings

answer

Because the human eye has a difficult time judging how much area is taken up by the wedge-shaped slice of a pie chart, which of the following is true of pie charts? They are only used for small data sets They are only used if they are made by a computer They are not commonly used by statisticians or in scientific settings They are preferred over bar graphs

question

mode

answer

When describing the distribution of a categorical variable, the category that appears most often is called the ____

question

Make an appropriate graph

answer

What is the first step in almost every investigation of data?

question

Change the scale of the vertical axis so that it does not start at 0

answer

What is the most common trick to mislead readers of bar graphs?

question

Decreasing the use of misleading graphics

answer

Which of the following is NOT a way in which the Internet is influencing statistical graphics? Decreasing the use of misleading graphics Increasing the use of interactive displays Allowing for a greater variety of graphical displays None of the above

question

mean

answer

The ____ is another term for the arithmetic average.

question

How many standard deviations away an observation is from the mean

answer

A standard unit measures what?

question

The observation is equal to the mean

answer

If an observation has a z-score of 0, what does that mean?

question

Z-Score

answer

What is used to compare values measured in different units, such as inches and pounds?

question

Mean and Median

answer

What are two measures of the center of distribution?

question

The median is preferred when the data is strongly skewed or has outliers

answer

Under what conditions is the use of the median preferred?

question

The mean is preferred when the data is relatively symmetric

answer

Under what conditions is the use of the mean preferred?

question

median

answer

The value that would be right in the middle if you were to sort the data from smallest to largest is called the ____

question

median interquartile range

answer

When a distribution is skewed, the ____ is used to measure the center and the ____ is used to measure variation.

question

resistant

answer

Because the median is not affected by the size of an outlier and does not change even if a particular outlier is replaced by an even more extreme value, we say the median is _____ to outliers.

question

The mean tends to be greater than the median

answer

In a right-skewed distribution which of the following is true? The mean tends to be less than the median The mean and median are approximately the same The mean tends to be greater than the median None of these

question

median

answer

In a boxplot, the vertical line inside the box marks the location of the _____.

question

IQR

answer

The length of the box in a boxplot is proportional to what?

question

1.5

answer

In a boxplot, potential outliers are points that are more than _____ IQRs from the edges of the box.

question

To the most extreme values that are not potential outliers

answer

In a boxplot, the whiskers extend to?

question

The minimum Q1 The Median Q3 The mamimum

answer

What are the fiver numbers needed to make a boxplot?

question

Variation

answer

Which of the following is NOT something that one looks for when studying scatterplots? Shape Variation Strength Trend

question

a positive association

answer

Since, in general, the longer a car is owned the more miles it travels one can say there is a ______ between age of car and mileage.

question

weak

answer

A large amount of scatter in a scatterplot is an indication that the association between the two variables is ____.

question

trend shape strength context

answer

When describing two-variable associations, a written description should always include what?

question

correlation coefficient (r)

answer

The _____ is a number that measures the strenth of the linear association between two numerical variables.

question

variables are numerical

answer

The correlation coefficient (r) makes sense only if the trend is linear and the ____

question

-1 and 1

answer

The correlation coefficient (r) is always a number between ____

question

Never

answer

When can a correlation coefficient (r) based on an observational study be used to support a claim of cause and effect?

question

It has no effect on r

answer

When computing the correlation coefficient (r), what is the effect of changing the order of the variables on r?

question

regression equation

answer

The ____ is a tool for making predictions about future observed values and is a useful way of summarizing a linear relationship.

question

"predicted"

answer

Statisticians often write the word ____ in front of the y-variable in the equation of the regression line.

question

least squares line

answer

Another name for the regression line is the ____ line.

question

To make predictions about the values of y for a given x-value

answer

An important use of the regression line is to do what?

question

predictor variable explanatory variable independent variable

answer

When writing a regression equation, what are names for the x-variable?

question

predicted variable response variable dependent variable

answer

When writing a regression equation, what are names for the y-variable?

question

answer

The intercept of a regression line tells a person the predicted mean y-value when the x-value is ___

question

A big effect

answer

What type of effect can outliers have on a regression line?

question

Do regression and correlation with and without these points and comment on the differences

answer

When on has influential points in their data, how should regression and correlation be done?

question

influential

answer

Since outliers can greatly affect the regression line they are also called ____ points

question

extrapolation

answer

Attempting to use the regression equation to make predictions beyond the range of the data is called _____

question

coefficient of determination

answer

The value that measures how much variation in the response variable is explained by the explanatory variable is called the ____.

question

variance = s² = (∑(x-x̄)²/(n-1)

answer

Variance is another measure of variability and is used if the distribution is symmetric. What is the variance formula?

question

r = (∑ZxZy)/n-1

answer

The correlation coefficient (r) measures the strength of a linear association. What is its formula?

question

z = (x-x̄)/s

answer

A z-score converts observations into standard units. Its formula is?

question

a = ȳ - bx̄

answer

The formula for the intercept (a) of a regression line is?

question

68% 95%

answer

What percentage of the observations will be within one standard deviation of the mean? Within two?

question

IQR = Q₃ - Q₁

answer

The interquartile range is the measurement of variability best used when the distribution is skewed. Its formula is?

question

mean = x̄ = ∑x/n

answer

The mean is the measure of center best used if the distribution is symmetric. Its formula is?

question

"Predicted" y = a + bx

answer

The regression line summarizes the relationship of a distribution. The regression line formula is?

question

Maximum - Minimum

answer

The range is a crude measure of variability. It's formula is?

question

b = r(Sy/Sx)

answer

The formula for the slope (b) of a regression line is?

question

Standard Deviation = s = √(∑(x-x̄)²/(n-1)

answer

The standard deviation is the measure of variability best used if the distribution is symmetric. The formula for standard deviation is?

Accounting
AP Statistics
Computer Graphics
Iterative And Incremental
Mean And Standard Deviation
Net Book Value
Software Engineering
Statistics
System Development Life Cycle

C179 Study Guide – Fill in the Blanks – Flashcards 117 terms
Blake Terry

117 terms
Preview

C179 Study Guide – Fill in the Blanks – Flashcards

question

Data is _______ _________ without further meaning.

answer

raw facts

question

Information is data that an Information System (IS) has ________________ into meaningful information.

answer

transformed

question

Good Information Chracteristics

answer

Accurate (free from errors), Timely (available when needed), Relevant (appropriate), Sufficient (the right amount), Reliable Cost-Effective (cost doesn't outweigh benefits).

question

Two types of Information decisions

answer

Structured - follows a formula Unstructured - possibly several answers would work

question

Managerial Information Systems

answer

Executive - highly summarized Managerial - tactical decision making based upon Exec. Operational - Structured, detailed

question

Five Component Parts in Information System

answer

Hardware, Software, Data, Procedures, People (Howard, Saw, Dana, Poke, Peter)

question

Information Granularity

answer

Course - Highly Summarized, usually a report. Fine - Highly detailed useful for low level managers

question

3 Roles in Information Systems

answer

Computer User - Basic, can operated the system Super User - Understands the IS and how it works Expert User - Can operate, train and convert old to new

question

Business Process

answer

is a network of activities, repositories, roles, resources and flows (series of steps) that interact to accomplish a business function.

question

Fully Automated Process

answer

network of IS takes inventory, reduces stock, tracks buying trends and identifies times to reorder. (Walmart)

question

Partially Automated Process

answer

Staff counts inventory, inputs inventory in spreadsheet or data collection tool and executes a purchase electronically. (small grocery)

question

Fully Manual Process

answer

items manually weighed, sold, and verbally providing the customer the price. (Farmers Market)

question

Business Process Engineering Phases

answer

Create As-Is, Create Components, Implement Process, Assess Results

question

Business Process Engineering - Phase 1

answer

Create an As-Is Model. Ensures understanding of the Current Process

question

Business Process Engineering - Phase 2

answer

Create the Components (Hw, Sw, Data, Proc. People)

question

Business Process Engineering - Phase 3

answer

Implement the processes, which should be more efficient, streamlines, and easier than the old process.

question

Business Process Engineering - Phase 4

answer

Assess the results, to monitor the effectiveness of the new processes.

question

Process Modeling

answer

a graphic representation, using process modeling notation, of how data flow and how activities are related in an organization.

question

Process Modeling Symbol - Rectangle

answer

Activity

question

Process Modeling Symbol - Diamond

answer

Decision / Gateway

question

Process Modeling Symbol - Page

answer

Data

question

Process Modeling Symbol - Dashed Line

answer

Data Flows

question

Process Modeling Symbol - Solid Line

answer

Control Flows

question

Components of the Business Process

answer

Activities, Resources, Facilities, Data Flows

question

What are Facilities

answer

storage areas (warehouses or Databases)

question

Organizational Strategy

answer

the alignment of a companies planning, decisions, and actions to enable it to reach its goals, mission, objectives

question

2 reasons why organizations create information systems

answer

1. obtain its goals, objectives or mission. 2. solve a major problem or meet a challenge

question

Michael Porter's Five Forces Model - Reasons

answer

1. better understand the industry 2. determine how attractive the prospect of starting a business in a given industry. 3. how to conduct a successful business in a given industry

question

Porter's Five Forces 1

answer

Rivalry

question

Porter's Five Forces 2

answer

Threat of Substitution -

question

Porter's Five Forces 3

answer

Customer Bargaining Power - customer influence

question

Porter's Five Forces 4

answer

Supplier's Power - influence from a supplier

question

Porter's Five Forces 5

answer

Threat of New Entrant

question

Porter's Generic Strategies Model Reasoning

answer

1. Businesses leverage their strengths to select the strategy for best success 2. identify the best way to operate

question

Porter's Generic Strategies 1

answer

Broad Cost Leadership - Across a industry

question

Porter's Generic Strategies 2

answer

Broad Differentiation - Unique

question

Porter's Generic Strategies 3

answer

Narrow Cost Leadership

question

Porter's Generic Strategies 4

answer

Narrow Differentiation

question

Broad Cost Leadership Strategy

answer

reduced overall production/distribution cost, and appeal to cost-conscious customers. Lower prices (maintaining value (cost/quality)

question

Broad Differentiation Strategy

answer

products stand out, customers willing to pay premium price. Focus on satisfying under-served needs.

question

Narrow Cost Leadership Strategy

answer

focus on cost behavior on a smaller segment (southwest - only in certain markets and one type of aircraft)

question

Narrow Differentiation Strategy

answer

focus on one market segment (ferrari targets high performance car enthusiasts)

question

Value Chain

answer

network of value creating activities with primary activities that create value and secondary activities that indirectly contribute to value creation

question

Value Chain - Primary Activites

answer

Inbound Logistics, Operations, Outbound Logistics, Marketing and Sales, Service

question

Value Chain - Secondary Activities

answer

Procurement, Human Resources, Technological Development, Infrastructure

question

Advantages using Value Chain Analysis

answer

Identify inefficiencies, enhancing activities, modifying activities, identifying weak information systems

question

Approaching an IS using Porter's model - steps

answer

1. Five Forces - understanding of the forces the company faces in the industry 2. generic strategies - organization develop the best way to compete. 3. Value Chain - enables the org to break down processes to look for opportunities.

question

Tasks to Determine Requirements - System Development

answer

1. Cooperate 2. Identify Expectations 3. Examine Previous Work 4. Ask Questions

question

The _____ a project the harder it is to change

answer

Larger

question

Budgeting Factors - Tools to Determine System Cost

answer

Cost Benefit Analysis Cost Projection Examining Past Projects and their Costs

question

Outsourcing Advantages

answer

1. Management Advantage 2. Cost Reduction (initially) 3. Risk Reduction (initially)

question

Outsourcing Disadvantages

answer

1. Loss of Control 2. Benefits eventually outweighed by overall cost 3. No Easy Exit

question

System Development Life Cycle (SDLC)

answer

a rigid, phased approach to system development. Usually offers a high chance for success.

question

Tools in System Development Life Cycle (SDLC)`

answer

Work Breakdown Structure (WBS) - outline view of tasks ordered by phases. Gantt Chart - displays tasks and dependencies

question

System Development Life Cycle (SDLC) Strengths

answer

1. Able to monitor and maintain control over large projects 2. detailed phases 3. Good documentation 4.Great input into requirements 5. Easy System Maintenance 6. Staff changes do not impact development

question

System Development Life Cycle (SDLC) Weaknesses

answer

1. Longer Development time 2. Higher Cost 3. needs well-defined systems at the beginning 4. Rigid Process 5. difficulty estimating scheduling and budgeting 6. Limited user input

question

System Development Life Cycle (SDLC) Phases

answer

Planning, Analysis, Design, Implementing, Maintenance

question

System Development Life Cycle (SDLC) Phase 1

answer

Planning - define the scope - conduct feasibility studies - form a project team

question

System Development Life Cycle (SDLC) Phase 2

answer

Analysis - identify system requirements - identify system object requirements - identify system security requirements - identify personnel procedures - create a data model

question

System Development Life Cycle (SDLC) Phase 3

answer

Design - HW - SW - DB - Create job descriptions - Create system procedures

question

System Development Life Cycle (SDLC) Phase 4

answer

Implementation - Build the system - test the system - - - Unit Test - - - User Test - Conversion - - - Parallel - - - Pilot - - - Plunge - Training

question

System Development Life Cycle (SDLC) Phase 5

answer

Maintenance - Resolve request for revisions - Addressing reported problems - Issuing Patches

question

Prototyping

answer

building a preliminary model of a proposed finished system / temporary systems that don't include all functionality

question

Prototyping advantages

answer

1. Development time / cost is reduced 2. Systems likely to fulfill user requirements 3. User involvement provide valueable feedback 4. Users adapt easily to finished system

question

Prototyping Disadvantages

answer

1. Users use prototypes as final systems 2. Documentation is incomplete 3. expectations are high and lead to disappointment of final system 4. prototyping can not accommodate large amounts of users

question

Prototyping Steps

answer

1. Identify 2. Develop 3. Test 4. Refine

question

Prototyping is an __________ approach

answer

iterative

question

Object Orientated Development (OOD) is _________ System

answer

unstructured

question

Polymorphism

answer

ability to appear in different forms (object appearing as a subobject)

question

Encapsulation

answer

act of storing data and procedures together in an object

question

Inheritance

answer

allows an object to inherit properties from objects in different classes

question

Classes

answer

collections of similar objects that can contain subclasses

question

Objects

answer

entities that can interact with one another

question

Object Orientated Development (OOD) Advantages

answer

1. Code is modified easily using other objects 2. objects are reusable 3. objects are modular 4. Security is easy to set in program code

question

Object Orientated Development (OOD) Disadvantages

answer

1. Code is difficult to read and understand 2. OOD is ineffective at representing non-objects 3. it takes longer to execute routines 4. fewer functions 5. not user friendly 6. extensive evaluation and monitoring

question

Rapid Application Development (RAD)

answer

a methodology that enables a rapid development process for systems while maintaining an acceptable level of quality.

question

Rapid Application Development (RAD) Qualities

answer

- Accomplished in small groups - prototyping and iterative testing - reuses software components - uses visual programming - 80/20

question

Rapid Application Development (RAD) develops softaware by ________ and ________ existing software components into a new system

answer

assembling, integrating (Component based Development)

question

Rapid Application Development (RAD) Life Cycle

answer

1. Requirements Planning 2. User Design 3. Construction 4. Implementation

question

Rapid Application Development (RAD) Advantages

answer

1. Good when scope is limited 2. Good when requirements are not complex 3. Quick response 4. Flexible 5. Extensive User Participation 6. Fast

question

Rapid Application Development (RAD) Disadvantages

answer

1. less scalable, may not contain all the features 2. more costly 3. quality problems 4. needs not adequately met 5. less efficient 6. Prone to Problems

question

Agile Systems Methodology Advantages

answer

1. breaks tasks into small increments with minimal planning -no long term planning 2. Iterations are short time frames (1-to 4 weeks) - - Each iteration involve planning, requirements analysis, design, coding, unit testing, and acceptance testing. 3. Small crossfunctional teams 4. Face to Face communications / Stand-Up Meetings 5. Working software is the primary measure of progress. 6. More adaptive to project changes than predictive.

question

Agile Systems Methodology is based on...

answer

iterative and incremental development.

question

Extreme Programming (XP) is

answer

customer-driven, agile process

question

Extreme Programming (XP) response well to changes because....

answer

of checkpoints that enable customer feedback and review

question

Extreme Programming (XP) 12 core practices

answer

1. Customer Defines application with User Stories 2. XP team puts small code into production 3. xp use common system names and descriptions 4. simply written, object orientated code meets requirements 5. wirtes automated uint tests upfront uses through out the process. 6. frequent revise and edit of unit code (Refactoring)

question

Extreme Programming (XP) 12 core practices (part 2)

answer

7. Pair Programming 8. Collective Ownership of code 9. integrate code and save to repository every couple hours 10. programmers work full time 11. Customer Rep onsite through out development 12. common coding structure

question

Extreme Programming (XP) Phases

answer

1. Planning 2. Designing 3. Coding 4. Testing 5. Listening Please, Don't, Chew, The, Line

question

XP Advantages

answer

1. A focus on Programming code for quick delivery of features 2. A quality methodology for smaller systems, resulting in low cost compared with other methodologies 3. Simple design, because each feature is coded, tested, and implemented independent of other functionalities 4. Continuous testing for ensuring quality feature development 5. Robustness, because each feature is listed along with a cost estimate for organizations to rank feature development 6. Resilience, because changes can be made late in the system's development life cycle, incorporated into development, and used without going back to an earlier phase as in other methodologies 7. Reduced risk in Programming and coding because two programmers work on each feature: one writing code and one testing it 8. High employee satisfaction because of users' intense involvement during the entire development process 9. The ability to add features at any time during the development process without negatively affecting development

question

XP Disadvantages

answer

1. Scant documentation because of the lack of design-centered approach usually followed in larger systems development projects 2. The potential for user conflicts to bog down the development when agreements are hard to reach 3. Unstable requirements because of the lack of a formal requirements analysis before design and Programming are done 4. Limited overall design specifications because features are designed as needed. 5. Methodology geared toward single projects; not good for large projects 6. Does not work well when scalability issues exist because they cannot be integrated with other programs later 7. Constant contact with the customer is assumed, which can be difficult to ensure if users are ambivalent or do not want to be a part of the development team

question

Systems-Type Audit

answer

ensures an org system and applications are appropriate and contrlled to maintain security and reliability

question

Process-Type Audit

answer

includes a risk analysis of new and existing projects to determine how organizations compare

question

Successful management of IS......

answer

1. keeps systems from being obsolete 2. integrating systems to avoid duplication 3. strategic approach 4. data integrity without duplication, inconsistencies and errors

question

Chief Information Officer (CIO)

answer

highest ranking exec, responsible for all IS within the org.

question

IS Departments

answer

Technology, Operations, Development Outsourcing, Data Admin

question

IS (or IT) departments responsible for...

answer

User ID, Granting access and permissions, ensuring systems have data integrity, managing the security of data.

question

Ethics are...

answer

moral guidelines in organizations.

question

2 questions in ethics

answer

1. was harm done to anyone 2. did someone gain an undeserved advantage from the behavior.

question

Approaches to Managing Ethics

answer

1. Informal Approach - address as occurs 2. General Written Procedures 3. Written Code of Ethics 4. Top down Ethics Approach

question

Important Steps in Promoting Ethics

answer

1. Inform employees about policies and procedures 2. incorporate ethics in all areas of the organization 3. train employees how to recognize unethical behavior 4. help avoid circumstances 5. Hold Formal Training

question

Threats to Information System

answer

1. Unintentional 2. intentional

question

Types of Threats

answer

1. Natural 2. Human 3. Environmental 4. Physical 5. Technical

question

Aspects to consider in a security plan

answer

1. Hardware Security 2. Software Security 3. Data Security 4. People Security

question

Physical Safegards

answer

1. ID Badges 2. Cubical Design 3. Shredder

question

Acts of Congress that require Data backups

answer

1. Sarbanes-Oxley Act 2. HIPPA 3. Gramm-Leach-Bliley Act (GLBA)

question

Types of Media for Backups

answer

1. Optical 2. Semiconductor 3. Magnetic 4. Cloud

question

Organizations spend ____% of their IT budget on disaster recovery

answer

2-4%

question

Disaster Recovery Plans (DRP) Objectives

answer

1. decrease risk of disaster 2. decrease probability of disaster 3. decrease insurance premiums 4. protect assets 5. reduce dependencies on human decision making 6. organization stability 7. improve employee safety

question

Disaster Recovery Plans (DRP) Steps

answer

1. Select DRP Team - entire organization 2. conduct a risk analysis 3. identify recovery options 4. Create a DRP strategy - - - key contacts - - - HW / SW considerations - - - Data Files - - - Communications and Infrastructure - - - Org Facilities - - - Hot / Cold Sites

question

Types of protected data

answer

1. Business Financial Data 2. Personally Identifiable Information (Customer Data)

question

Data Safeguards should ensure

answer

1. Confidentiality 2. Integrity 3. Availability

question

If you are aware / witness a security compromise or breach

answer

1. protect company and customer 2. identify offender 3. limit damage 4. alert customers 5. help in the resolution of security incidents. 6. enable policies and procedures to be effective.

question

Problem Management Benefits

answer

1. Reduce number of errors/incidents 2. Quality of Service Improves 3. Increased Organizational Knowledge 4. Proactive problem management

question

Proactive

answer

work done to resolve issues before they are reported

question

Reactive

answer

customer initiates problem solving, contacting customer support

question

Problem Management Steps -

answer

1. Record 2. Classify / Categorize 3. Check the incident against known issues. 4. Track Progress 5. Provide closure

question

Change Management Stages

answer

1. Acceptance and Filtering 2. Classification 3. Formal Approval 4. Building, Testing and Implementing 5. Post Implementation Review

AP Statistics
Probability And Statistics
Statistics

Statistics Chapter 1 – Flashcards 57 terms
Sara Edwards

57 terms
Preview

Statistics Chapter 1 – Flashcards

question

Define Statistics [C-O-S-A]

answer

The science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions while providing confidence in any conclusion

question

Define Individual

answer

A person or object that is a member of the population being studied

question

Descriptive Statistics

answer

Consists of organizing and summarizing information collected

question

Inferential Statistics

answer

Uses methods that generalize results obtained from a sample to the population and measure the reliability of the results

question

Define STATISTIC

answer

A numerical summary of a SAMPLE

question

Define Parameter

answer

A numerical summary of a POPULATION

question

Define Variables

answer

The characteristics of the individuals of the population being studied

question

In a national survey of 1300 high school students (grades 9 to 12), 32% of respondents reported that someone had bullied them at school. Is 32% a parameter or a statistic?

answer

Statistic

question

The average score for a class of 28 students taking a calculus exam was 72%. Is 72% a parameter or a statistic?

answer

Parameter

question

Qualitative vs. Quantitative

answer

Qualitative [Phone Number] Quantitative [Number of Siblings] [Grams of Carbs in Doughnut]

question

Continuous vs. Discrete

answer

Continuous is a decimal [ Length in minutes of a country song] Discrete is a whole number [Points scored by a soccer player in a season]

question

Nominal

answer

If values of variable name, label, or categorize. CAN NOT BE RANKED IN ORDER [Eye Color]

question

Ordinal

answer

Can be ranked in certain order [Movie ratings of one star through five stars]

question

Interval

answer

Addition and subtraction can be performed on the values of the variable [Year of birth of college students] (You wouldn't multiply this-no reason to)

question

Ratio

answer

Multiplication and division can be performed on the values of the variable [Assessed value of a house]

question

Observational Study

answer

Measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. RESEARCHER OBSERVES THE BEHAVIOR OF THE INDIVIDUALS WITHOUT TRYING TO INFLUENCE THE OUTCOME OF THE STUDY

question

Designed Experiment

answer

Researcher assigns the individuals in a study to a certain group, intentionally changes the value of an explanatory variable and then records the value of the response variable for each group [allows researcher to claim causation between an explanatory variable and a response variable]

question

What is meant by confounding?

answer

It exists in a study when the effects of two or more explanatory variables are not separated. So any relation that appears to exist between a certain explanatory variable and the response variable may be due to some other variable not accounted for in the study

question

What is a lurking variable?

answer

Not accounted for in the study but affects the value of the response variable

question

What is a cross-sectional study?

answer

Collect information at a specific point in time

question

What is a case control study?

answer

Retrospective. Individuals that have a certain characteristic in a case control study are matched with those that do not have the characteristics

question

What does it mean when an observational study is retrospective?

answer

Looks at data from the past either through recall or records

question

What does it mean when an observational study is prospective?

answer

Gathers data over time by following the individuals in the study and recording data as they occur

question

7th grade students are randomly divided into 2 groups. 1 group is taught math using traditional techniques. The other is taught math using a reform method. After 1 year each group is given an achievement test to compare proficiency. Is this an observational study or an experiment?

answer

Experiment

question

A survey is conducted asking 400 people "Do you prefer coke or pepsi?"

answer

Observational study

question

What is a frame?

answer

A list of the individuals in the population we are studying

question

What does it mean when sampling is done without replacement?

answer

Once an individual is selected he or she cannot be selected again

question

How do you obtain a simple random sample of size 3 from the list of 9?

answer

You can write each name on paper and choose the names out of hat or number the books 1-9 and randomly select three numbers

question

Which sampling method does not require a frame?

answer

Systematic

question

A __ sample is obtained by dividing the population into groups and selecting all individuals from within a random sample of the group

answer

CLUSTER

question

A__sample is obtained by dividing the population into homogeneous groups and randomly selecting individuals from each group

answer

STRATIFIED

question

True or False: When taking a systematic random sample of size n, every group of size n from the population has the same chance of being selected

answer

FALSE

question

True or False: A simple random sample is always preferred because it obtains the same information as other sampling plans but requires a smaller sample size

answer

FALSE

question

True or False: When conducting a cluster sample, it is better to have fewer clusters with more individuals when the clusters are heterogeneous

answer

TRUE

question

True or False: Inferences based on voluntary response samples are generally not reliable

answer

TRUE

question

True or False: When obtaining a stratified sample, the number of individuals included within each stratum must be equal

answer

FALSE

question

Systematic Example

answer

To estimate the % of defects in a recent manufacturing batch, a quality control manager at Intel selected every 8th chip that comes off the assembly line starting with the 3rd until she obtains a sample of 140 chips

question

Cluster Example

answer

To determine customer opinion of its boarding policy, southwest airlines randomly selects 60 flights during a certain week and surveys all passengers on the flights

question

Simple Random Sample Example

answer

In an effort to identify whether an advertising campaign has been effective, a marketing firm conducts a nationwide poll by randomly selecting individuals from a list of known users of the product

question

Convenience Sample Example

answer

A survey regarding download time on a certain Web site is administered on the Internet by a market research firm to anyone who would like to take it

question

Stratified Example

answer

To determine his DSL Internet connection speed, Shawn divides up the day into four parts: morning midday, evening, and late night. He then measures his Internet connection speed at 5 randomly selected times during each part of the day

question

Closed Question?

answer

Has fixed choices for answers: Easier to analyze limit the response

question

Open Question?

answer

Is a free response question: allow respondents to state exactly how they feel but are harder to analyze due to variety

question

What does it mean when a part of the population is under-represented?

answer

A certain segment of the population is not represented in the sample proportionally to its size in the population

question

Distinguish between nonsampling error and sampling error

answer

Nonsampling is the error that results from UNDERCOVERAGE, NONRESPONSE BIAS, RESPONSE BIAS, DATA ENTRY ERRORS. It is the error that comes from the process of obtaining the data. Sampling is the error that results because a sample is being used to estimate info about a population

question

Why is it rare for frames to be completely accurate?

answer

Frames are obtained periodically whereas populations are constantly changing

question

What are some solutions to nonresponse?

answer

Callbacks, incentives

question

Discuss the benefits of having trained interviewers

answer

Better survey results. Trained interviewers can elicit responses to difficult questions

question

What are the advantages of having a presurvery when constructing a questionnaire that has closed questions?

answer

The researcher can learn common answers

question

Experimental Unit

answer

A person object or some other well defined item upon which a treatment is applied

question

Treatment

answer

Any combo of the values of the factors [explanatory variables]

question

Response Variable

answer

A quantitative or qualitative variable that represents the variable of interest

question

Factor

answer

The variable whose effect on the response variable is to be assessed by the experimenter

question

Placebo

answer

An innocuous medication such as a sugar tablet that looks tastes and smells like the experimental medication

question

Confounding

answer

The effect of two factors on the response variable cannot be distinguished.

question

Explain the difference between a single blind and double blind experiment

answer

Single Blind: the subject doesn't know which treatment is received. Double Blind: neither the subject nor the researcher in contact with the subject knows which treatment is received

question

True or False: Generally the goal of an experiment is to determine the effect that treatments will have on the response variable

answer

True

Elementary Statistics
Statistics

elementary statistics ch. 1 – Flashcards 68 terms
Ethan Carter

68 terms
Preview

elementary statistics ch. 1 – Flashcards

question

data

answer

collections of observations, such as measurements, genders, or survey responses.

question

datum

answer

a single data vaule

question

statistics

answer

science of planning studies and experiments; obtaining data; and then organizing, summarizing, presenting, analyzing, and interpreting those data and then drawing conclusions based on them

question

population

answer

the complete collection of all measurements or data that are being considered

question

cesus

answer

the collection of data from every member of the population

question

sample

answer

a subcollection of members selected from a population

question

voluntary response sample (self-selected sample)

answer

one in which the respondents themselves decide whether to be included

question

statistical significance

answer

achieved in a study when we get a result that is very unlikely to occur by chance

question

practical significance

answer

it is possible that some treatment or finding is effective, but common sense might suggest that the treatment or finding does not make enough of a difference to justify its use or the be practical

question

how to find the percentage of

answer

% of respondents = %/100 x respondents

question

parameter

answer

a numerical measurement describing some characteristic of a population

question

statistic

answer

a numerical measurement describing some characteristic of a sample

question

quantitative (numerical)

answer

data consists of numbers representing counts or measurements

question

categorical (qualitative or attribute)

answer

data consists of names or labels that are not numbers representing counts or measurements

question

discrete data

answer

results when the data values are quantitative and the number of value is finite or countable

question

discrete

answer

what type of data would be used when you count the number of coin tosses before getting tails?

question

continuous data

answer

result from infinitely many possible quantitative values, where the collection of values is not countable

question

nominal level of measurement

answer

characterized by data that consists of names, labels, or categories only. the data cannot be arranged in an ordering scheme (such as low to high)

question

ordinal level of measurement

answer

they can be arranged in some order, but difference (obtained by subtraction) between data values either cannot be determined or are meaningless

question

interval level of measurement

answer

they can be arranged in order, and differences between data values can be found and are meaningful.

question

interval

answer

data at this level do not have a natural zero starting point at which none of the quantity is present

question

ratio level of measurement

answer

they can be arranged in order, difference can be found and are meaningful, and there is a natural zero starting point (where zero indicates that none of the quantity is present)

question

ratio

answer

for this data level both differences and ratios are meaningful

question

observational study

answer

we observe and measure specific characteristics, but we don't attempt to modify the subjects being studied

question

experiment

answer

we apply some treatment and then proceed to observe its effects on the subject

question

simple random sample

answer

of n subjects is selected in such a way that every possible sample of the same size of n has the same chance of being chosen

question

systematic sampling

answer

we select some starting point and then select every kth (such as every 50th) element in the population

question

convenience sampling

answer

we simply use results that are easy to get

question

stratified sampling

answer

we subdivide the population into at least two different subgroups (or strata) so that subjects within the same subgroup share the same characteristics (such as age bracket). then we draw a sample from each subgroup (or stratum)

question

cluster sampling

answer

we first divide the population area into sections (or cluster) then we randomly select some of those clusters and choose all the members from those selected clusters

question

multistage sample design

answer

pollsters select a sample in different stages, and each state might use different methods of sampling

question

cross-sectional study

answer

date are observed, measured, and collected at one point in time, not over a period of time

question

retrospective study

answer

date are collected from a past time period by going back in tie (through examination or records, interviews, and so on)

question

case-control

answer

what is another name for retrospective study?

question

prospective study

answer

data are collected in the future from groups that share common factors (such groups are called cohorts)

question

longitudinal or cohort

answer

what is another name for the prospective study?

question

randomization

answer

used when subjects are assigned to different groups through a process of random selection

question

replication

answer

the repetition of an experiment on more than one subject

question

blinding

answer

is in effect when the subject doesn't know whether he or she is receiving a treatment or a placebo

question

placebo effect

answer

occurs when an untreated subject reports an improvement in symptoms

question

double-blind

answer

blinding occurred at two levels; the subject and the experimenter are not aware if the subject is receiving a placebo

question

confounding

answer

occurs in experiment when the investigators are not able to distinguish among the effects of different factors

question

sampling error

answer

occurs when the sample has been selected with a random method, but there is a discrepancy between a sample result and the true population result; such as an error results from chance samples fluctuations

question

nonsampling result

answer

is the result of human error, including such factors as wrong data entries, computing errors, questions with biased wording, false data provided by respondents, forming biased conclusions, or applying statistical methods that are not appropriate for the circumstances

question

nonrandom sampling error

answer

is the result of using a sampling method that is not random, such as using a convenience sample or a voluntary response sample

question

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless volume of brains in cubic centimeters

answer

the ratio level is of measurement is most appropriate because the data can be ordered, differences can be found and are meaningful, and there is a natural starting 0 point

question

determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below: flight numbers

answer

the nominal level of measurement is most appropriate because the data cannot be ordered.

question

determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below: favorite sport

answer

nominal

question

determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below: ratings on a scale from 1 to 4 stars

answer

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless

question

determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below: internet speed levels of "fast," "medium," and "slow"

answer

the ordinal level of measurement is the most appropriate because categories are ordered, but difference (obtained from subtraction) cannot be found or are meaningless

question

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless people's age

answer

the ratio level is of measurement is most appropriate because the data can be ordered, differences can be found and are meaningful, and there is a natural starting 0 point

question

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless surveys response of "yes," "no," and "no opinion"

answer

the nominal level of measurement is most appropriate because the data cannot be ordered.

question

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless hair colors

answer

nominal

question

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless stress scores when the mean is zero and the increments of measurement are equal

answer

the interval level of measurement is the most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is no natural 0 starting point.

question

the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless body temperature in degrees of Fahrenheit

answer

the interval level of measurement is the most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is no natural 0 starting point.

question

Determine whether the description below corresponds to an observational study or an experiment. in a survey sponsored by a company, 10,797 people were asked what contributes most to their sadness, and 20% of the respondents said that it was their partner.

answer

the study is an observational study because the survey subjects were not given any treatment.

question

Determine whether the description below corresponds to an observational study or an experiment. research in conducted to determine if is a relation between colon cancer and fat consumption

answer

observational study

question

Determine whether the given description corresponds to an observational study or an experiment. In a study of 360 children with a particular disease, the subjects completed a survey about their diet.

answer

The given description corresponds to an observational study.

question

Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. A woman experienced a tax audit. The tax department claimed that the woman was audited because everyone in five randomly selected districts was being audited.

answer

cluster sampling

question

Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. A man is selected by a marketing company to participate in a paid focus group. The company says that the man was selected because he was randomly chosen from all men in his tax bracket.

answer

stratified sampling

question

Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. To determine customer opinion of their service, Business Depot randomly selects 70 stores during a certain week and surveys all customers present in the store.

answer

cluster sampling

question

Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. asks its viewers to call in their opinion regarding the desirability of programs in high definition TV.

answer

convenience sampling

question

Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. A researcher selects every 806th social security number and surveys the corresponding person.

answer

systematic sampling

question

Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. A man is selected by a marketing company to participate in a paid focus group. The company says that the man was selected because he was randomly chosen from all adults.

answer

random sampling

question

Determine whether the sample described below is a simple random sample. A quality control engineer selects every 15,000th raisin that is produced.

answer

The sample is not a simple random sample because every sample of the same size does not have the same chance of being selected.

question

Determine whether the sample described below is a simple random sample. In the last year, 185,674 adults paid taxes in a county. A researcher plans to conduct a survey of 500 of those taxpayers. After obtaining a list of those who paid taxes, he numbers the list from 1 to 185,674, and then he uses a computer to randomly generate 500 numbers between 1 and 185,674. His sample consists of the taxpayers corresponding to the selected numbers.

answer

The sample is a simple random sample because every sample of size 500 has the same chance of being selected.

question

Determine whether the sample described below is a simple random sample. According to a realtors association, names of potential house buyers are selected from a variety of different sources. Names from the list are randomly selected in a way that is equivalent to writing the names on slips of paper, mixing them in a bowl, and selecting the required number of potential house buyers.

answer

The sample is a simple random sample because every sample of the same size has the same chance of being selected.

question

Determine whether the sample described below is a simple random sample. In order to test for a difference in the way that workers and non-workers purchase magazines, a research institution polls exactly 623 adult workers and 623 adult non-workers randomly selected from adults in the United States.

answer

The sample is not a simple random sample because every sample of size 1246 does not have the same chance of being selected.

AP Statistics
Discrete Or Continuous Data Set
Elementary Statistics
Statistics

Stat Math – Flashcard 102 terms
Maxim Beck

102 terms
Preview

Stat Math – Flashcard

question

What is voluntary response sample?

answer

A sample in which the subjects themselves decide whether to be included in the study.

question

Which of the following is typically the important factor to consider when conducting a statistical analysis of data?

answer

1. Sampling method 2. Context of the data 3. Source of the data

question

What does it mean for the findings of a statistical analysis of data to be statistically significant?

answer

The likelihood of getting these results by chance is very small.

question

If we are collecting sample data for a study, the _ that we choose can greatly influence the validity of our conclusions. For example, we can use sound statistical methods to analyze data in voluntary response samples, but the results are not necessarily valid.

answer

sampling method

question

How do parameter and statistic differ?

answer

A parameter is a numerical measurement of a population; a statistic is a numerical measurement of a sample.

question

Which of the following is associated with a parameter?

answer

Data that were obtained from an entire population.

question

Why is a voluntary response sample generally unsuitable for methods of statistics?

answer

People with special interests are more likely to respond, so the sample is likely to be biased.

question

What is the goal of learning statistics?

answer

To learn to distinguish between statistical conclusions that are likely to be valid and those that are seriously flawed.

question

What is a self-interest study?

answer

A survey in which the sponsor can enjoy monetary or other gains from the results.

question

What is the difference between a random sample and a simple random sample?

answer

With a random sample, each individual has the same chance of being selected. With a simple random sample, all samples of the same size have the same chance of being selected.

question

Which sampling method divides the population up into sections, randomly selects some of those sections, then choose all the members from the selected sections to study?

answer

Cluster

question

Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each subdivision?

answer

Stratified

question

_is used when subjects are assigned to different groups through a process of random selection.

answer

Randomization

question

Which of the following corresponds to the case when every sample of size n has the same chance of being chosen?

answer

Simple random sample

question

Which characteristic of data is a measure of the amount that the data values vary?

answer

Variation

question

_are sample values that lie very far away from the majority of the other sample values.

answer

Outliers

question

A frequency distribution helps us understand the nature of the distribution of a data set.

answer

Frequency distribution

question

Class width is found by

answer

subtracting a lower class limit from the next consecutive lower class limit

question

In a relative frequency distribution, the frequency of a class is replaced with a proportion or percent.

answer

relative frequency

question

The heights of the bars of a histogram correspond to frequency values.

answer

frequency

question

The bars in a histogram touch.

answer

touch

question

A histogram aids in analyzing the _ of the data.

answer

shape of the distribution

question

A _ histogram has the same shape and horizontal scale as a histogram but the vertical scale is marked with relative frequencies instead of actual frequency.

answer

relative frequency

question

A(n)_distribution has a "bell" shape.

answer

normal

question

What are some advantages of a dotplot over a frequency polygon

answer

A dotplot allows you to identify the original data values.

question

A(n)_uses line segments to connect points located directly above class midpoint values.

answer

frequency polygon

question

A_is a graph of each data value plotted as a point.

answer

dotplot

question

We utilize statistical _ to look for features that reveal some useful or interesting characteristics of the data set.

answer

graphs

question

A _ is a plot of paired data (x,y) and is helpful in determining whether there is a relationship between the two variables.

answer

scatterplot

question

In a graph, if one or both axes begin at some value other than zero, the differences are exaggerated. This bad graphing method is known as _

answer

a nonzero axis

question

When drawings of objects are used to depict data, false impressions can be made. These drawings are called _

answer

pictographs

question

Which of the following is a common distortion that occurs in graphs

answer

Using a two-dimensional object to represent data that are one-dimensional in nature.

question

Why is it important to learn about bad graphs?

answer

So that we can critically analyze a graph to determine whether it is misleading.

question

Methods used that summarize or describe characteristics of data are called _ statistics.

answer

descriptive

question

A value at the center or middle of a data set is a(n) _

answer

measure of center

question

The measure of center that is the value that occurs with the greatest frequency is the _

answer

mode

question

The measure of variation that is very sensitive to extreme values

answer

Range

question

The Range Rule of Thumb roughly estimates the standard deviation of a data set as _

answer

s=range/4

question

For data sets having a distribution that is approximately bell-shaped, _ states that about 68% of all data values fall within one standard deviation from the mean.

answer

the Empirical Rule

question

The square of the standard deviation is called the_

answer

variance

question

When a data value is converted to a standardized scale representing the number of standard deviations the data value lies from the mean, we call the new value a _

answer

z-score

question

A data value is considered _ if its z-score is less than -2 or greater than 2

answer

unusual

question

Whenever a data value is less than the mean, _

answer

the corresponding z-score is negative

question

In modified boxplots, a data value is a(n) outlier if it is above Q3+(1.5)(IQR) or below Q1-(1.5)(IQR).

answer

outlier

question

The _ for a procedure consists of all possible simple events or all outcomes that cannot be broken down any further.

answer

sample space

question

The classical approach to probability requires that the outcomes are _

answer

equally likely

question

As a procedure is repeated again and again, the relative frequency of an event tends to approach the actual probability. This is known as _

answer

the law of large numbers

question

The _ event A occurring are the ratio P(A)/(P(A-)

answer

actual odds in favor of

question

When using the _ always be careful to avoid double-counting outcomes.

answer

addition rule

question

Events that are _ cannot occur at the same time

answer

disjoint

question

P(A) + P(A-) = 1 is one way to express the _

answer

rule of complementary events

question

P(A or B) indicates

answer

the probability that in a single trial, event A occurs, event B occurs, or they both occur.

question

A _ is any event combining two or more simple events.

answer

compound event

question

Describe what the notation P(BlA) represents.

answer

The probability of event B occurring, given that event A has already occurred.

question

A picture of line segments branching out from one starting point illustrating the possible outcomes of a procedure is called a _

answer

tree diagram

question

Two events A and B are _ if the occurrence of one does not affect the probability of the occurrence of the other.

answer

independent

question

Selections made with replacement are considered to be _

answer

independent

question

"At least one" is equivalent to_

answer

"one ore more"

question

The complement of "at least one" is _

answer

"none"

question

A conditional probability of an event is a probability obtained with knowledge that some other event has already occurred.

answer

conditional

question

P(BlA) = P(AlB)

answer

Confusion of the inverse occurs when we incorrectly believe _

question

The conditional probability of B given A can be found by _

answer

assuming that event A has occurred, and then calculating the probability that event B will occur

question

Discrete Data

answer

result when the number of possible values is either a finite number or a "countable" number. (That is, the number of possible values is 0 or 1 or 2, and so on.)

question

Continuous Data

answer

also known as numerical data, result from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps, interruptions, or jumps

question

Determine whether the value given below is from a discrete or continuous data set: When a car is randomly selected and weighed, it is found to weigh 1950.3kg

answer

A continuous data set because there are infinitely many possible values and those values cannot be counted

question

Nominal

answer

Level of measurement is characterized by data that consist of names, labels, or categories only

question

Ordinal

answer

Data are at the ordinal level of measurement if they can be arranged in some order

question

Interval

answer

Is like the ordinal: Data are at the ordinal level of measurement if they can e arranged in some order with the additional property that the difference between any two data values is meaningful

question

Ratio

answer

The ratio level of measurement is the interval level with the additional property that there is also a natural zero starting point.

question

Determine whether the source given below has the potential to create a bias in a statistical study. A certain medical organization tends to oppose the use of meat and dairy products in our diets, and that organization has received hundreds of thousands of dollars in funding from an animal foundation.

answer

There does appear to be a potential to create a bias. There is an incentive to produce a results that are in line with the organization's creed and that of its funders.

question

Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 764 subjects, each was asked how often he or she read a book. The survey subjects were internet users who responded to a question that was posted on a news website.

answer

It is flawed because it is a voluntary response samples

question

Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 759 human resource professionals, each was asked about the importance of the experience of a job applicant. The survey subjects were randomly selected by pollsters from a reputable market research firm.

answer

It appears to be sound because the data are not biased in any way

question

Determine whether the results below appear to have statistical significance, and also determine whether the results have practical significance, In a study of a weight loss program, 7 subjects lost an average of 50lbs. It is found that there is about a 38% chance of getting such results with a diet that has no effect.

answer

Does the weight loss program have statistical significance? No, the program is not statistically significant because the results are likely to occur by chance. Does the weight loss program have practical significance? Yes, the program is practically significant because the amount of weight loss is large enough to be considered practically significant.

question

Several studies showed that after eating chocolate, subject had increased blood levels of antioxidants. Antioxidants have been associated with decreased risk of heart disease. A candy company financed this research. What is wrong with this study?

answer

Self-interest study

question

Based on a study of weights of men and women who are vegetarian, a researcher concludes that eating vegetables causes people to loose weight. Do you agree with this conclusion?

answer

No, There may be a relationship between a vegetarian diet and weight loss, but that does not mean that one causes the other

question

An ad for seat belts claimed that proper usage of seat belts reduces the chance of fatality in a car crash by 300 percent. What is wrong with this statement?

answer

If seat belts eliminated all fatalities, it would result in a 100% reduction, so it is not possible to reduce fatalities by more than 100%

question

An ad for a device used to discourage bike thefts stated that "This device reduces your odds of bike theft by 350 percent." What is wrong with this statement?

answer

If the device eliminated all bike thefts, it would reduce odds of bike theft by 100% so the 350% figure is misleading.

question

Which of the following is typically the least important factor to consider when conducting a statistical analysis of data?

answer

Formula calculation

question

Which of the following is NOT a voluntary response sample?

answer

Quiz scores from a college level statistics course are analyzed to determine student progress

question

Survey questions may be misleading if they are "loaded." To what does "loaded" refer?

answer

Intentionally worded to elicit a desired response

question

Which of the following is NOT a measure of center?

answer

census

question

Which of the following is NOT a characteristic of the mean?

answer

The mean is called the average by statisticians

question

The symbol for standard deviation?

answer

s

question

The symbol for population standard deviation?

answer

a symbol that resembles a Q

question

The symbol for sample variance?

answer

s squared

question

The symbol for population sample variance?

answer

a symbol that resembles a Q squared

question

What is the difference between statistical significance and practical significance? Can a statistical study have statistical significance, but not practical significance?

answer

Statistical significance is indicated when methods of statistics are used to reach a conclusion that some treatment or finding is effective, but common sense might suggest that the treatment or finding does not make enough of a difference to justify its use or to be practical. Yes, it is possible for a study to have statistical significance but not practical significance.

question

In conducting a statistical study, why is it important to consider the source of the data?

answer

It is important to consider the source of data when conducting a statistical study because some sources may put a spin on the results to obtain favorable results for their gain.

question

What is a voluntary response sample, and why is such a sample generally not suitable for a statistical study?

answer

A voluntary response sample is one in which the subjects themselves decide whether or not to be included in the study. Voluntary response samples are generally not suitable for a statistical study because we can draw valid conclusions only about the specific group of people who chose to participate and the sample may have a bias resulting from participation by those with a special interest in the topic being studied.

question

What is meant by the statement "the correlation does not imply causation?"

answer

A correlation is an association between two variables, such as driving a nice car and owning a nice house. There is a correlation between driving a nice car and owning a nice house, but driving a nice car does not cause a person to own a nice house.

question

Determine whether the given source has the potential to create a bias in a statistical study: The Physicians Committee for Responsible Medicine tends to oppose the use of meat and dairy products in our diets, and that organization has received hundreds of thousands of dollars in funding from the Foundation to Support Animal Protection.

answer

There does appear to be a potential to create bias.

question

Determine whether the given source has the potential to create a bias in a statistical study: Data set I in Appendix B includes body measurements obtained by the U.S. Department of Health and Human Services, National Center for Health Statistics.

answer

There does not appear to be a potential to create a bias.

question

Determine whether the given source has the potential to create a bias in a statistical study: Data Set 17 includes word counts obtained by members of the Departments of Psychology at the University of Arizona, Washington University, and the University of Texas at Austin.

answer

There does not appear to be a potential to create a bias.

question

Determine whether the given source has the potential to create a bias in a statistical study: An article in Journal of Nutrition noted that chocolate is rich in flavonoids. The article notes that "regular consumption of foods rich in flavonoids may reduce the risk of coronary heart disease." The study received funding from Mars, Inc., the candy company, and the Chocolate Manufacturers Association.

answer

There does appear to be a potential to create a bias.

question

Determine whether the sampling method appears to be sound or is flawed: A survey of 721 subjects involved the providing of personal information when using Wi-Fi hotspots. The survey subjects were Internet users who responded to a question that was posted on the electronic edition of USA Today.

answer

The sample is a voluntary response sample and is flawed.

question

Determine whether the sampling method appears to be sound or is flawed: In a survey of 109 subjects, each was asked to indicate how many text messages they send and receive each day. The sample consisted of those who chose to respond to the request posted on the StatCrunch Web site.

answer

The sample is a voluntary response sample and is flawed.

question

Determine whether the sampling method appears to be sound or is flawed: In a survey of 514 human resource professionals, each was asked about the importance of the appearance of a job application. The survey subjects were randomly selected by Harris Interactive pollsters.

answer

The sampling method appears to be sound.

question

Determine whether the sampling method appears to be sound or is flawed: In a survey of beliefs about evolution, Gallup pollsters randomly selected and telephoned 1018 adults in the United States.

answer

The sampling method appears to be sound.

question

Determine whether the results appear to have statistical significance, and also determine whether the results have practical significance: In a study of the Marisa Waite diet, four subjects lost an average of 45 pounds. It is found that there is about a 30% of getting such results with a diet that has no effect.

answer

Because there is a 30% chance of getting such results with a diet that has no effect, it does not appear to have statistical significance, but the average loss of 45 pounds does appear to have practical significance.

question

Determine whether the results appear to have statistical significance, and also determine whether the results have practical significance: In a study of the Gender Aide method of gender selection, 1000 users of the method gave birth to 540 boys and 460 girls. There is about a 1% chance that such extreme results would occur if the method had no effect.

answer

Because there is a 1% chance that such results would occur if the method had no effect, is appears to have statistical significance, but it does not appear to have practical significance.

question

Determine whether the results appear to have statistical significance, and also determine whether the results have practical significance: When making random guesses for difficult multiple-choice test questions with possible answers of a, b, c, d, and e, we expect to get about 20% of the answers correct. The Ashton Prep Program claims to have developed a better method of guessing. In a test of that program, guesses were made for 100 answers, and 23 were found to be correct. There is a 23% chance of getting such results if the program has no effect.

answer

Because there is a 23% chance of getting such results if the program has no effect, it does not appear to have statistical significance. Because the success rate of 23% is not that much better than the 20% rate, it does not appear to have practical significance.

question

Determine whether the results appear to have statistical significance, and also determine whether the results have practical significance: Most people have IQ scores between 70 and 130. For $32, you can purchase a computer program from Highiqpro.com that is claimed to increase your IQ score by 10 to 20 points. The program claims to be "the only proven IQ increasing software in the brain training market," but the author of your text could find no data supporting that claim, so let's suppose that these results were obtained: In a study of 12 subjects using the program, the average increase in IQ is 3 IQ points. There is a 25% chance of getting such results if the program has no effect.

answer

Because there is a 25% chance of getting such results if the program has no effect, it does not appear to have statistical significance. Because the average increase in IQ from the study was only 3 IQ points, while the program claimed to improve your IQ by 10 to 20 points, there does not appear to have practical significance.

Cross Sectional Data
International System Of Units
Problem Solving
Statistics
Time Series Data

C451 / INC1 WGU Integrated Natural Sciences 3/2016 – Flashcards 73 terms
Elizabeth Mcdonald

73 terms
Preview

C451 / INC1 WGU Integrated Natural Sciences 3/2016 – Flashcards

question

Observations

answer

A collection of measurements, notes, images, etc. to describe a phenomenon

question

Reproductive Result

answer

Different Researchers following the published methods finding the same result

question

Conclusion

answer

The summary of the results of an experiment or set of experiments

question

Theory

answer

Synthesis of information and well-tested hypotheses; may be disputed

question

Hypothesis

answer

A scientific idea undergoing testing

question

Ohms

answer

Used to measure for resistance to an electrical current

question

Micrometers

answer

Used to measure the diameter of a lung alveoli

question

Joules

answer

Used to measure work done pushing a refrigerator across a room

question

Millivolts

answer

Used to measure the potential difference across a nerve synapse

question

Liters

answer

Used to measure the volume of air that can be inhaled in a single breath

question

Mechanical Advantage of a Lever

answer

A small input force applied to one end of a lever produces a large output force at the opposite end of the lever

question

Physics

answer

The study of Electricity, electrical circuits, forces, energy, heat, sound, light, and subatomic energies

question

Astronomy

answer

The study of stars and planets

question

Earth Science

answer

The study of geology, meteorology and oceanography

question

Biology

answer

The study of living organisms

question

Chemistry

answer

The study of the interactions between compounds and molecules

question

A Hypotheses must be?

answer

Falsifiable and results must be repeatable

question

A systems approach to scientific study?

answer

Enables scientists to take into account the various parts of a system when making predictions about system behavior

question

Law

answer

A law is widely accepted by the scientific community

question

Creativity

answer

Enables scientists to come up with new hypotheses

question

Big Bang Theory

answer

Account for the beginning of both time and space in the universe

question

Produces a decrease in Gravitational and electrical force between two objects

answer

Increasing the Distance between objects and decreasing the electrical charge and the mass of both objects

question

The primary thermonuclear reaction that occurs in our Sun

answer

A certain mass of hydrogen atoms is fused together every second to become a lesser mass of helium atoms, and the missing mass is released as radiant energy

question

Two phenomena are the result of gravity between the Moon and the Earth

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One side of the Moon always facing Earth and Phases of the Moon

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How does cosmic background radiation with a wavelength of 7.35cm help support the big bang theory?

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The wavelength matches the predicted value for the current temperature of the universe and radiation is coming from all directions with no specific source

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White Dwarf

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Star no longer undergoing fusion

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Red Giant

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Star near it's final stage of evolution, burns helium as it's primary fuel and begins to have carton build-up in the core; type of star the Sun will become

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Main-Sequence Star

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Star burns hydrogen as its primary fuel

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Three helium nuclei combine to form a carbon nucleus, releasing light energy

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Process of Thermonuclear fusion in a helium-burning star

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Electromagnetic Waves with Frequency higher than that of visible light

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Gamma Rays, Ultraviolet and X-Rays

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Electromagnetic Waves with Frequency lower than that of visible light

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Radio Waves, Infrared and Microwaves

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Order of the objects, increasing in distance from the Sun

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Mercury, Venus, Earth, Mars, Astroid Belt, Jupiter, Saturn, Uranus and Neptune

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Jupiter

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Has a very strong magnetic field that produces the highest radiation levels ever measured and is the most massive planet

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Pluto

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Composed primarily of rock and nitrogen ice

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Saturn

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Has the lowest density of any planet

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Radio Waves

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Electromagnetic wave is used to transmit AM/FM radio stations

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X-Rays

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Electromagnetic wave is used to identify broken bones

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Ultraviolet

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Electromagnetic wave is used to kill bacteria and sanitize instruments

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Microwaves

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Electromagnetic wave is used to cook and heat food

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Gamma Rays

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Electromagnetic wave is used in medicine for cancer treatment?

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Metamorphic Rocks

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Contain minerals from igneous or sedimentary rocks, can be foliated and are recrystallized

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Granite

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Coarse-grained and plutonic

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Marble

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Large interlocking crystals of calcite, non foliated and metamorphic

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Silicate

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Four oxygen atoms joined to one silicon atom in a tetrahedron

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Diamond

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Carbon arranged in a crystal lattice

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Magnetism

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Deflects moving charged particles, is perpendicular to current flowing through a wire and causes a directional needle in a compass to rotate

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Electricity

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Occurs when there is a difference in Electrical Potential and is measured as current

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How Table Salt is Bonded together

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Electrons in the salt are transferred to form cations and anions, Chlorine and Sodium fill their outermost energy shells by donating or gaining electrons

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Water reacts to Freezing by?

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Decreasing transitional energy, move into a more orderly arrangement and move slight away from each other

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Crust

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Contains the highest concentration of silica

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Core

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Composed primarily of nickel and iron and cannot be penetrated by S-Waves

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Mantle

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Contains iron-rich silicate rock

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The Himalayan Mountain range is produced by what tectonic movements?

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A continental plate is colliding with another continental plate, causing upward motion and a lithospheric plate is colliding with another lithospheric plate of similar buoyancy

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Effects of the Earth's Hadley Cells

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Trade Winds, Regions of high rainfall in the tropics and clear skies in the subtropical desert

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Kinetic Energy

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Energy in motion (i.e. Propagation of sound, driving in a straight line at a constant speed)

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Chemical Potential Energy

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Stored Energy in Chemicals (i.e. Energy stored in glucose, random molecular motion)

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Gravitational Potential Energy

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Stored Energy in objects being acted upon by gravity

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Law of Conservation of Energy

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Energy cannot be created or destroyed

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Radio Waves Transferred by?

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Vibrating electric and magnetic fields force electrons in the receiving antenna to vibrate at the same frequency

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Newton's 3rd Law of Motion

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For every action, there is an equal and opposite reaction.

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Role of Solar Energy

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Warms air at the equator which rises and spreads towards the poles, circulating in large convection currents and plants covert carbon dioxide and water into glucose and oxygen through photosynthesis

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Two most Abundant gases in Earth Atmosphere

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Oxygen & Nitrogen

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Seismometers

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Used to measure earthquake magnitude and infer the structure of the Earth's Interior

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Abiotic and Biotic relationship in a forest ecosystem

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Solar energy enabling plants to create organic molecules

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First Tropic Level

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Plants and algae make their own food and are called primary producers

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Second Trophic Level

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Herbivores eat plants and are called primary consumers

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Third Trophic Level

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Carnivores that eat herbivores are called secondary consumers

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Fourth Trophic Level

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Carnivores that eat other carnivores are called tertiary consumers

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Fifth Trophic Level

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Apex predators that have no predators are at the top of the food chain

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Plants

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Multicellular terrestrial photosynthetic autotrophs

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Fungi

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Single-celled heterotroph used in baking

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Animals

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Multicellular heterotrophs that obtain nutrients by ingestion and heterotrophs with an exoskeleton

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Protists

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A single-sealed heterotroph that causes severe gastric distress in it's host