Bstat chapter 2
Unlock all answers in this set
Unlock answersquestion
A stem-and-leaf display is a graphical portrayal of a data set that shows the data set's overall pattern of variation.
answer
true
question
The relative frequency is the frequency of a class divided by the total number of measurements.
answer
true
question
A bar chart is a graphic that can be used to depict qualitative data
answer
true
question
Stem-and-leaf displays and dot plots are useful for detecting outliers.
answer
true
question
A scatter plot can be used to identify outliers.
answer
false
question
When looking at the shape of the distribution using a stem-and-leaf, a distribution is skewed to the right when the left tail is shorter than the right tail.
answer
true
question
When we wish to summarize the proportion (or fraction) of items in a class we use the frequency distribution for each class.
answer
false
question
When establishing the classes for a frequency table it is generally agreed that the more classes you use the better your frequency table will be.
answer
false
question
The sample cumulative distribution function is non-decreasing.
answer
true
question
A frequency table includes row and column percentages.
answer
false
question
A(n) ______ is a graph of a cumulative distribution.
answer
Ogive plot
question
________ can be used to study the relationship between two variables.
answer
Crosstabulation tables
question
Row or column percentages can be found in:
answer
Crosstabulation tables
question
All of the following are used to describe quantitative data except the
answer
pie chart
question
An observation separated from the rest of the data is a(n)
answer
outlier
question
Which of the following graphs is for qualitative data?
answer
Bar Chart
question
A Stem and Leaf display is best used to
answer
Display the shape of the distribution.
question
When grouping a large sample of items into classes, the ______________ is a better tool than the ___________.
answer
Histogram, stem and leaf display
question
A ______________ displays the frequency of each group with qualitative data and a ____________ displays the frequency of each group with quantitative data.
answer
Bar chart, histogram
question
A ______________ shows the relationship between two variables
answer
Scatter Plot
question
A ______________ can be used to differentiate the "vital few" causes of quality problems from the "trivial many" causes of quality problems.
answer
Pareto chart
question
______________ and _____________ are used to describe qualitative (categorical) data.
answer
Bar charts, pie charts
question
Which one of the following statistical tools is used with quantitative data?
answer
Histogram
question
When developing a frequency distribution the class (group), intervals should be
answer
mutually exclusive.
question
Which of the following graphical tools is not used to study the shapes of distributions?
answer
Scatter plot
question
All of the following are used to describe qualitative data except the:
answer
Histogram
question
If there are 130 values in a data set, how many classes should be created for a frequency histogram?
answer
8
question
If there are 120 values in a data set, how many classes should be created for a frequency histogram?
answer
7
question
If there are 62 values in a data set, how many classes should be created for a frequency histogram?
answer
6
question
If there are 30 values in a data set, how many classes should be created for a frequency histogram?
answer
5
question
A CFO is looking at how much of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf
answer
Skewed to the right
question
A CFO is looking at how much of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf
answer
5.2
question
A CFO is looking at how much of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf If a frequency histogram were to be created using these data, how many classes would you create?
answer
6
question
A CFO is looking at how much of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf What would be the class length that would be used in creating a frequency histogram?
answer
1.4
question
A CFO is looking at how much of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf
answer
5.2 - 6.4
question
The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below: How many flights were used in this plo
answer
12
question
The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below: In developing a histogram of these data, how many classes would be used?
answer
4
question
The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below: What would be the class length for creating the frequency histogram?
answer
1.7
question
A company collected the ages from a random sample of its middle managers with the resulting frequency distribution shown below: What would be the approximate shape of the relative frequency histogram?
answer
Skewed to the left
question
A company collected the ages from a random sample of its middle managers with the resulting frequency distribution shown below: What is the relative frequency for the largest interval?
answer
.283
question
A company collected the ages from a random sample of its middle managers with the resulting frequency distribution shown below: What is the midpoint of the third class interval?
answer
32.5
question
The 550 students answered an additional question with the following results based on their rating of their instructor: What proportion of the students who rated their instructor as very or somewhat effective received a B or better in the class?
answer
0.898
question
The 550 students answered an additional question with the following results based on their rating of their instructor: What proportion of all 550 students received less than a C?
answer
0.08
question
822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book What percentage of the books purchased were either mystery or science fiction/fantasy?
answer
36.5
question
822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book type: What percentage of the books purchased were self-help books?
answer
11.44%
question
822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book type: What percentages of books were in the top two categories?
answer
43.43
question
A graphical display of categorical data made up of vertical or horizontal bars is called a _____.
answer
bar chart
question
A flaw possessed by a population or sample unit is _____
answer
defect
question
A graphical portrayal of a data set that divides the data into classes and gives the frequency of each class is a(n) _____.
answer
Histogram
question
The number of measurements falling within a class interval is called the _____
answer
Frequency
question
A relative frequency curve having a long tail to the right is said to be _____.
answer
Skewed to the right
question
The percentage of measurements in a class is called the _____ of that class
answer
relative frequency
question
A histogram that tails out towards larger values is _____
answer
skewed to the right
question
A histogram that tails out towards smaller values is _____
answer
skewed to left
question
A(n) ___________ is a graphical display of categorical data made up of vertical or horizontal bars.
answer
bar chart
question
A __________ can be used to differential the "vital few" causes of quality problems from the "trivial many" causes of quality problems.
answer
Pareto chart
question
A ________ is a graph of cumulative distribution.
answer
Ogive plot
question
Using the following data, describe the shape of the data distribution
answer
skewed to rightt
question
Using the following data, what would be the range of the values of the stem in a stem and leaf display?
answer
11-18
question
Using the following data, what would be the leaf unit in a stem and leaf display?
answer
10
question
Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the shortest distance.
answer
.375
question
Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the distances over 24 miles
answer
.150
question
The following is a partial relative frequency distribution of grades in an introductory statistics course. Find the relative frequency for B grade
answer
.37
question
The following is a relative frequency distribution of grades in an introductory statistics course. If this was the distribution of 200 students, find the frequency for the highest two grades:
answer
118
question
The following is a relative frequency distribution of grades in an introductory statistics course. If this was the distribution of 200 students, find the frequency of failures
answer
12
question
The following is a relative frequency distribution of grades in an introductory statistics course. If we wish to depict these data using a pie chart, find how many degrees should be assigned to the highest grade of A.
answer
79.2
question
Recently an advertising company called 200 people and asked to identify the company that was in an ad running nationwide. The following results were obtained: What percentage of those surveyed were female and could not recall the company?
answer
22.0%
question
Recently an advertising company called 200 people and asked to identify the company that was in an ad running nationwide. The following results were obtained: What percentage of those surveyed could not correctly recall the company?
answer
58.00%
question
The local electronics retailer has recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. The following results were obtained: What percentage of purchases were Plasma televisions by customers with the smallest credit balances?
answer
19.6%
question
The local electronics retailer has recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. The following results were obtained: What percentage of the customers with the highest credit balances purchased an LCD television?
answer
5.9%
question
The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below: 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 How many classes should be used in the construction of a histogram?
answer
5
question
The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below: 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 What is the shape of the distribution of the data?
answer
skewed right
question
The number of items rejected daily by a manufacturer because of defects for the last 30 days are: 20, 21, 8, 17, 22, 19, 18, 19, 14, 17, 11, 6, 21, 25, 4, 19, 9, 12, 16, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8 How many classes should be used in the construction of a histogram?
answer
5
