105 questioned Stats Review – Flashcards
97 test answers
Unlock all answers in this set
Unlock answers 97question
40 of the birth weights
answer
102
Unlock the answer
question
The number of children with birth weights between 102-122
answer
50%
Unlock the answer
question
Strongly Skewed to the left. Which combo of measure of center and spread?
answer
Median and IQR
Unlock the answer
question
Lobster fisherman
answer
14
Unlock the answer
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.
Unlock the answer
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
Unlock the answer
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.
Unlock the answer
question
Mr. William's calculus class
answer
79%
Unlock the answer
question
Pisaster arm length
answer
median - 15.2 IQR - 4.3
Unlock the answer
question
A Standard Score Describes
answer
How far a particular score is from the mean
Unlock the answer
question
Jack and Jill
answer
Jack - 1.07 Jill - 1.11 Jill Wins
Unlock the answer
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
Unlock the answer
question
if 30 is added to every number on the list, what DOES NOT change?
answer
Standard Deviation
Unlock the answer
question
Standard deviation of salaries
answer
Increase by 3,000
Unlock the answer
question
The IQR of the salaries for the employees
answer
be unchanged
Unlock the answer
question
The z scores of the salaries for the employees will
answer
be unchanged
Unlock the answer
question
Birthweights at a local hospital have a norm dist. with a mean of 110
answer
.136
Unlock the answer
question
IQ's among undergraduates at mountain tech are...
answer
5
Unlock the answer
question
A company produces ceramic floor tiles
answer
.3085
Unlock the answer
question
the time to complete a standardized exam
answer
78.4
Unlock the answer
question
You are chatting with the principal of a local high school
answer
M = 550 SD = 75
Unlock the answer
question
Etymologist Heinz Kaefer
answer
310
Unlock the answer
question
Basketball - Total Assists
answer
The distribution is skewed
Unlock the answer
question
The response variable
answer
the volume of lumber
Unlock the answer
question
Which of the following Statements are supported by the scatterplot
answer
I II III
Unlock the answer
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
Unlock the answer
question
Correlation coefficient measures
answer
the strength and direction of a linear relationship between two variables
Unlock the answer
question
Stopping distance vs. outside temperature... Correlation
answer
Approx. 0.6
Unlock the answer
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.
Unlock the answer
question
Intercept of Least Squares regression line is approx
answer
1.8
Unlock the answer
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
Unlock the answer
question
The point indicated by the open circle
answer
has a negative
Unlock the answer
question
Least Squares in the term Least Squares Regression line refers to
answer
minimizing the squares of all the values of the response variable.
Unlock the answer
question
Which of the following statements are true about the least squares regression line
answer
I II III
Unlock the answer
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
Unlock the answer
question
If removing an observation
answer
influential
Unlock the answer
question
Suppose a straight line is fit to data having
answer
Extrapolation.
Unlock the answer
question
The circled point on the scatter plot represents lima beans, which have 621 calories
answer
-4.18
Unlock the answer
question
Expected average error - LSRL Lima Bean
answer
3.37648
Unlock the answer
question
A study of child development measures the age
answer
the test scores gets down by 1.3 pts
Unlock the answer
question
equations - eggs
answer
Eggs = -142.74 + 39.25Length
Unlock the answer
question
Predicted y-values from the actual y-values
answer
25.55
Unlock the answer
question
You want to know the opinions of American school teachers... The population is
answer
2500 teachers chosen at random
Unlock the answer
question
A television station
answer
Voluntary Response Bias
Unlock the answer
question
a news release
answer
biased, overstating effect of diet
Unlock the answer
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.
Unlock the answer
question
In an experiment an observed effect so large that it would rarely occur
answer
Statistically significant
Unlock the answer
question
Another correct label for 816 students
answer
01-815 ID
Unlock the answer
question
A public opinion poll in ohio
answer
Stratified random sample
Unlock the answer
question
Stratified random sample addresses the same issues as
answer
block design
Unlock the answer
question
In the late 1990's Scotland was considering independence from England
answer
the wording of the question
Unlock the answer
question
frequently, telephone poll takers call near dinner time
answer
nonresponse
Unlock the answer
question
Which of the following is not a major principle of good design for all experiments
answer
blocking
Unlock the answer
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
Unlock the answer
question
The reason blocking is sometimes used in experimentation is to
answer
reduce variability arrising from random assignment
Unlock the answer
question
The probability that the next five babies are girls is
answer
.03125
Unlock the answer
question
The probability that at least one of the next three babies is a boy
answer
.875
Unlock the answer
question
The events A = the nest two babies are boys, and B = the nest two babies are girls are
answer
disjoint
Unlock the answer
question
In a certain town...
answer
30%
Unlock the answer
question
Suppose A and B are independent events with P(A) = .2 and P(B) = .4
answer
.12
Unlock the answer
question
The probability your score 4 points both times is
answer
.0277
Unlock the answer
question
P(A u B) ------ Red and Green
answer
5/6
Unlock the answer
question
The event corresponding to the system failing during one period of operation is
answer
F;G
Unlock the answer
question
Event A occurs with a probability of .8. The conditional probability that event B occurs, given that A occurs is .5
answer
.4
Unlock the answer
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
Unlock the answer
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
Unlock the answer
question
Probability that the student has breakfast
answer
.5
Unlock the answer
question
Given that the student who ate breakfast is selected what is the probability he is male
answer
.64
Unlock the answer
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
Unlock the answer
question
P(AuB)
answer
Q + S + R
Unlock the answer
question
P(AnB)
answer
r/(q+r)
Unlock the answer
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
Unlock the answer
question
If two students are selected at random, what is the probability that neither of them has a dog or cat
answer
.548
Unlock the answer
question
Let X be the outcome of rolling a fair six-sided die. P(1<X<5)=
answer
.5
Unlock the answer
question
An expression the represents the probability of at least one tail is
answer
P(x<3)
Unlock the answer
question
The probability of at least one tail is
answer
.9375
Unlock the answer
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 $4, and if the number of spots showing is 1, 2, or 3 you win nothing. Let Xbe the amount that you win. Use Scenario 6-2. Which of the following is the standard deviation of X?
answer
1.41
Unlock the answer
question
The probability that a random scratch card will pay off is
answer
.0601
Unlock the answer
question
The expected pay off per card
answer
.85
Unlock the answer
question
The mean number of customers that make a purchase during the first hour that the store is open
answer
3
Unlock the answer
question
The density curve for a continuous random variable X has which of the following properties
answer
All of the above
Unlock the answer
question
P(X>400$) is
answer
.2119
Unlock the answer
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
Unlock the answer
question
Albert - What is the expected value of Z
answer
1.2
Unlock the answer
question
Alberts Game- Standard deviation and mean
answer
M = 1.6 SD = 1.2
Unlock the answer
question
What is the expected value of T
answer
40
Unlock the answer
question
Typically the formula 1.07
answer
m = 42.78 sd = 6.09
Unlock the answer
question
The distribution of X = the number of questions the student will correct is
answer
binomial with parameters n = 20 and p = 0.25.
Unlock the answer
question
Which of the following expresses the probability that the student gets no questions correct?
answer
.75^20
Unlock the answer
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
Unlock the answer
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.
Unlock the answer
question
The Binomial expression
answer
.2731
Unlock the answer
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
Unlock the answer
