Question 1

The weights (in pounds)of 30 newborn babies are listed below.  
Choose the boxplot that represents the given data.
I II III

IV V

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 2

Here are some summary statistics for all of the runners in a local 12 kilometre race:
Slowest time = 121 minutes
Mean = 76 minutes
Median = 76 minutes
Range = 91 minutes
IQR = 57
Q1 = 30
Standard deviation = 13 minutes
Between what two values are the middle 50% of times?

Accepted Answer

A) 30 and 87 
B) 38 and 76 
C) 15.2 and 60.8 
D) 19 and 57 
E) 121 and 30 
A) 30 and 87 
B) 38 and 76 
C) 15.2 and 60.8 
D) 19 and 57 
E) 121 and 30

Question 3

The following stem-and-leaf display shows the number of homeless cats and dogs that had to be euthanized each year in a large city for the period 1985-2004.Use both the stemplot and timeplot to describe the distribution.

Accepted Answer

A) The distribution of the number of cats and dogs that were euthanized is skewed to the right,and has several modes,with gaps in between.One mode is clustered between 87,000 and 90,000 euthanized,a second mode at 84,000,and a third mode with a cluster between 81,000 and 82,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
B) The distribution of the number of cats and dogs that were euthanized is bimodal.The upper cluster is between 87,000 and 90,000 euthanized,with a centre at around 88,400.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.The timeplot shows that the number of animals euthanized has decreased over the period 1985-2004,with a significant decrease between 1994 and 1996. 
C) The distribution of the number of cats and dogs that were euthanized is bimodal.The upper cluster is between 87,000 and 90,000 euthanized,with a centre at around 88,400.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
D) The distribution of the number of cats and dogs that were euthanized is bimodal.The upper cluster is between 89,000 and 90,000 euthanized,with a centre at around 88,400.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
E) The distribution of the number of cats and dogs that were euthanized is skewed to the left,and has several modes,with gaps in between.One mode is clustered between 87,000 and 90,000 euthanized,a second mode at 84,000,and a third mode with a cluster between 81,000 and 82,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
A) The distribution of the number of cats and dogs that were euthanized is skewed to the right,and has several modes,with gaps in between.One mode is clustered between 87,000 and 90,000 euthanized,a second mode at 84,000,and a third mode with a cluster between 81,000 and 82,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
B) The distribution of the number of cats and dogs that were euthanized is bimodal.The upper cluster is between 87,000 and 90,000 euthanized,with a centre at around 88,400.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.The timeplot shows that the number of animals euthanized has decreased over the period 1985-2004,with a significant decrease between 1994 and 1996. 
C) The distribution of the number of cats and dogs that were euthanized is bimodal.The upper cluster is between 87,000 and 90,000 euthanized,with a centre at around 88,400.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
D) The distribution of the number of cats and dogs that were euthanized is bimodal.The upper cluster is between 89,000 and 90,000 euthanized,with a centre at around 88,400.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996. 
E) The distribution of the number of cats and dogs that were euthanized is skewed to the left,and has several modes,with gaps in between.One mode is clustered between 87,000 and 90,000 euthanized,a second mode at 84,000,and a third mode with a cluster between 81,000 and 82,000.The timeplot shows that the number of animals euthanized has increased over the period 1985-2004,with a significant increase between 1994 and 1996.

Question 4

The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below.

Accepted Answer

A) 3700 
B) 2500 
C) 310,2500,3700 
D) 2500,3700 
E) None 
A) 3700 
B) 2500 
C) 310,2500,3700 
D) 2500,3700 
E) None

Question 5

The weekly salaries (in dollars)of sixteen government workers are listed below.

Accepted Answer

A) 352,986 
B) 611 
C) 352 
D) 1086 
E) None 
A) 352,986 
B) 611 
C) 352 
D) 1086 
E) None

Question 6

Here are the highest temperatures ever recorded (in °F)in 32 different states in the U.S.A.  
Choose the boxplot that represents the given data.
I II III

IV V

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 7

The test scores of 15 students are listed below.

Accepted Answer

A) 41,54,69,86,95 
B) 41,51.50,72.0,85.5,95 
C) 41,51.50,69,85.5,95 
D) 41,52,72.0,87,95 
A) 41,54,69,86,95 
B) 41,51.50,72.0,85.5,95 
C) 41,51.50,69,85.5,95 
D) 41,52,72.0,87,95

Question 8

The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below.  
Choose the boxplot that represents the given data.
I II III

IV V

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 9

Use the high closing values of Naristar Inc.stock from the years 1990 - 2001 to construct a timeplot.

Accepted Answer

The answer of Use the high closing values of Naristar...

Question 10

Shown below are the boxplot,the histogram and summary statistics for the weights (in pounds)of 30 newborn babies:  
 
Write a few sentences describing the distribution.

Accepted Answer

A) The distribution is unimodal and symmetric.There are no outliers.The mean newborn baby weight was 6.9 lb with a standard deviation of 0.8 lb. 
B) The distribution is unimodal and symmetric.There are no outliers.The mean newborn baby weight was 7 lb with a standard deviation of 1.3 lb. 
C) The distribution is unimodal and skewed to the right.There are no outliers.The mean newborn baby weight was 7 lb with an IQR of 1.3 lb. 
D) The distribution is bimodal and symmetric.There are no outliers.The mean newborn baby weight was 6.9 lb with a standard deviation of 0.8 lb. 
E) The distribution is unimodal and skewed to the left.There are no outliers.The mean newborn baby weight was 7 lb with an IQR of 1.3 lb. 
A) The distribution is unimodal and symmetric.There are no outliers.The mean newborn baby weight was 6.9 lb with a standard deviation of 0.8 lb. 
B) The distribution is unimodal and symmetric.There are no outliers.The mean newborn baby weight was 7 lb with a standard deviation of 1.3 lb. 
C) The distribution is unimodal and skewed to the right.There are no outliers.The mean newborn baby weight was 7 lb with an IQR of 1.3 lb. 
D) The distribution is bimodal and symmetric.There are no outliers.The mean newborn baby weight was 6.9 lb with a standard deviation of 0.8 lb. 
E) The distribution is unimodal and skewed to the left.There are no outliers.The mean newborn baby weight was 7 lb with an IQR of 1.3 lb.

Question 11

Shown below are the boxplot and the histogram for the weekly salaries (in dollars)of 24 randomly selected employees of a company:  
i.What features of the distribution can you see in both the histogram and the boxplot?
ii.What features of the distribution can you see in the boxplot that you could not see in the histogram?

Accepted Answer

A) i)The distribution is unimodal and skewed to the right,with two outliers at $2500 and about $3700.The mean is greater than the median because of the skewedness.
ii.You can more easily tell from the boxplot that the median is about $700 with quartiles at about $500 and $1200. 
B) i)The distribution is symmetrical,with two outliers at $2900 and about $3000.The mean and median are about the same.
ii.You can more easily tell from the boxplot that the mean is about $500 with quartiles at about $700 and $1800. 
C) i)The distribution is unimodal and skewed to the left,with two outliers at $2500 and about $3700.The mean is lower than the median because of the skewedness.
ii.You can more easily tell from the boxplot that the median is about $900 with quartiles at about $1100 and $1600. 
D) i)The distribution is unimodal and skewed to the right,with two outliers at $2900 and about $3000.The mean is greater than the median because of the skewedness.
ii.You can more easily tell from the boxplot that the median is about $700 with quartiles at about $500 and $1200. 
E) i)The distribution is symmetrical,with two outliers at $2500 and about $3700.The mean and median are about the same.
ii.You can more easily tell from the boxplot that the mean is about $700 with quartiles at about $500 and $1200. 
A) i)The distribution is unimodal and skewed to the right,with two outliers at $2500 and about $3700.The mean is greater than the median because of the skewedness.
ii.You can more easily tell from the boxplot that the median is about $700 with quartiles at about $500 and $1200. 
B) i)The distribution is symmetrical,with two outliers at $2900 and about $3000.The mean and median are about the same.
ii.You can more easily tell from the boxplot that the mean is about $500 with quartiles at about $700 and $1800. 
C) i)The distribution is unimodal and skewed to the left,with two outliers at $2500 and about $3700.The mean is lower than the median because of the skewedness.
ii.You can more easily tell from the boxplot that the median is about $900 with quartiles at about $1100 and $1600. 
D) i)The distribution is unimodal and skewed to the right,with two outliers at $2900 and about $3000.The mean is greater than the median because of the skewedness.
ii.You can more easily tell from the boxplot that the median is about $700 with quartiles at about $500 and $1200. 
E) i)The distribution is symmetrical,with two outliers at $2500 and about $3700.The mean and median are about the same.
ii.You can more easily tell from the boxplot that the mean is about $700 with quartiles at about $500 and $1200.

Question 12

Here are summary statistics for the time,in minutes,it took for 20 people to complete an information survey at a walk-in medical clinic.  
Would you describe this distribution as symmetric or skewed?

Accepted Answer

A) Skewed to the left,because the mean is smaller than the median and the upper quartile is farther from the median than the lower quartile. 
B) Skewed to the right,because the mean is smaller than the median and the lower quartile is farther from the median than the upper quartile. 
C) Symmetric,because the mean and the median are close. 
D) Skewed to the right,because the mean is larger than the median and the upper quartile is farther from the median than the lower quartile. 
E) Skewed to the left,because the mean is smaller than the median and the lower quartile is farther from the median than the upper quartile. 
A) Skewed to the left,because the mean is smaller than the median and the upper quartile is farther from the median than the lower quartile. 
B) Skewed to the right,because the mean is smaller than the median and the lower quartile is farther from the median than the upper quartile. 
C) Symmetric,because the mean and the median are close. 
D) Skewed to the right,because the mean is larger than the median and the upper quartile is farther from the median than the lower quartile. 
E) Skewed to the left,because the mean is smaller than the median and the lower quartile is farther from the median than the upper quartile.

Question 13

The normal monthly precipitation (in inches)for August is listed for 20 different cities in the U.S.A..  
Choose the boxplot that represents the given data.
I II III

IV V

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 14

Here are 3 boxplots of weekly gas prices at a service station in the U.S.A.(price in $ per gallon).Compare the distribution of prices over the three years.

Accepted Answer

A) Gas price have been increasing on average over the 3-year period,but the spread has been decreasing.The distribution has been skewed to the left,and there were 3 high outliers in 2005. 
B) Gas price have been increasing on average over the 3-year period,and the spread has been increasing as well.The distribution has been skewed to the right,and there were 3 high outliers in 2005. 
C) Gas price have been decreasing on average over the 3-year period,and the spread has been decreasing.The distribution has been skewed to the left,and there were 3 high outliers in 2005. 
D) Gas price have been decreasing on average over the 3-year period,but the spread has been increasing.The distribution has been skewed to the right,and there were 3 high outliers in 2005. 
E) Gas price have been increasing on average over the 3-year period,and the spread has been increasing as well.The distribution has been skewed to the left,and there were 3 high outliers in 2005. 
A) Gas price have been increasing on average over the 3-year period,but the spread has been decreasing.The distribution has been skewed to the left,and there were 3 high outliers in 2005. 
B) Gas price have been increasing on average over the 3-year period,and the spread has been increasing as well.The distribution has been skewed to the right,and there were 3 high outliers in 2005. 
C) Gas price have been decreasing on average over the 3-year period,and the spread has been decreasing.The distribution has been skewed to the left,and there were 3 high outliers in 2005. 
D) Gas price have been decreasing on average over the 3-year period,but the spread has been increasing.The distribution has been skewed to the right,and there were 3 high outliers in 2005. 
E) Gas price have been increasing on average over the 3-year period,and the spread has been increasing as well.The distribution has been skewed to the left,and there were 3 high outliers in 2005.

Question 15

Here are boxplots of the points scored during the first 10 games of the basketball season for both Caroline and Alexandra.The coach can take only one player to the state championship.Which one should she take knowing that she would like a safe player?

Accepted Answer

A) Alexandra,because she is the more consistent player. 
B) Both of them,because both girls have a median score of about 18 points per game. 
C) Caroline,because she is the more consistent player. 
D) Caroline,because the IQR is the largest. 
E) Alexandra,because the IQR is the largest. 
A) Alexandra,because she is the more consistent player. 
B) Both of them,because both girls have a median score of about 18 points per game. 
C) Caroline,because she is the more consistent player. 
D) Caroline,because the IQR is the largest. 
E) Alexandra,because the IQR is the largest.

Question 16

The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below,and displayed on the following boxplot.  
Find the IQR and the standard deviation.Which is the most appropriate measure of spread?

Accepted Answer

A) IQR: $789.3;standard deviation: $740
The IQR is the most appropriate measure of centre,because of the outliers. 
B) IQR: $715;standard deviation: $769
The standard deviation is the most appropriate measure of centre,because of the outliers. 
C) IQR: $715;standard deviation: $769
The standard deviation is the most appropriate measure of centre,because the outliers are not significant in the distribution. 
D) IQR: $715;standard deviation: $769
The IQR is the most appropriate measure of centre,because the outliers are not significant in the distribution. 
E) IQR: $715;standard deviation: $769
The IQR is the most appropriate measure of centre,because of the outliers. 
A) IQR: $789.3;standard deviation: $740
The IQR is the most appropriate measure of centre,because of the outliers. 
B) IQR: $715;standard deviation: $769
The standard deviation is the most appropriate measure of centre,because of the outliers. 
C) IQR: $715;standard deviation: $769
The standard deviation is the most appropriate measure of centre,because the outliers are not significant in the distribution. 
D) IQR: $715;standard deviation: $769
The IQR is the most appropriate measure of centre,because the outliers are not significant in the distribution. 
E) IQR: $715;standard deviation: $769
The IQR is the most appropriate measure of centre,because of the outliers.

Question 17

Use the high closing values of Naristar Inc.stock from the years 1992 - 2003 to construct a timeplot.

Accepted Answer

The answer of Use the high closing values of Naristar...

Question 18

Shown below are the boxplot and summary statistics for the heights,in centimetres,of a class of Grade 3 students in Halifax,NS.  
Which measures of centre and spread would you use for this distribution?

Accepted Answer

A) Median and standard deviation,because the outlier affects the mean. 
B) Mean and standard deviation,because the outlier affects the mean. 
C) Mean and IQR,because the outlier does not really affect the mean. 
D) Median and IQR,because the outlier significantly affects the mean. 
E) Mean and standard deviation,because the outlier does not really affect the mean. 
A) Median and standard deviation,because the outlier affects the mean. 
B) Mean and standard deviation,because the outlier affects the mean. 
C) Mean and IQR,because the outlier does not really affect the mean. 
D) Median and IQR,because the outlier significantly affects the mean. 
E) Mean and standard deviation,because the outlier does not really affect the mean.

Question 19

A local ice cream shop hand scoops each of its ice cream cones.The cones vary in weight from 126 grams to 291 grams with a mean of 181 grams and a standard deviation of 34 grams.The quartiles and median weights are 157,255,and 202 ounces.A customer makes a special order of a 448 ounce cone.
Which of the summary statistics might not change if that data value was added to the distribution?

Accepted Answer

A) Median,range 
B) Range,SD 
C) Q1,Q3 
D) Mean,IQR 
E) Median,IQR 
A) Median,range 
B) Range,SD 
C) Q1,Q3 
D) Mean,IQR 
E) Median,IQR

Question 20

A student at a local university took a total of 20 exams during freshman year.The student recorded the exam scores as percentages and created the following stem-and-leaf display.The lower stem contains leaves with the digits 0-4 and the upper stem contains leaves with digits 5-9.In addition to describing the distribution,give a reason to account for the shape of this distribution.  
Key:
9 | 2 = 92%

Accepted Answer

A) The distribution of exam scores is skewed to the right.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
B) The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the upper 80s and lower 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
C) The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
D) The distribution of exam scores is skewed to the left.Typically,the student scored 93% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
E) The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s. 
A) The distribution of exam scores is skewed to the right.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
B) The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the upper 80s and lower 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
C) The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
D) The distribution of exam scores is skewed to the left.Typically,the student scored 93% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores. 
E) The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.

Exam 4: Understanding and Comparing Distributions

The weights (in pounds)of 30 newborn babies are listed below. Choose the boxplot that represents the given data. I II III IV V

Here are some summary statistics for all of the runners in a local 12 kilometre race: Slowest time = 121 minutes Mean = 76 minutes Median = 76 minutes Range = 91 minutes IQR = 57 Q1 = 30 Standard deviation = 13 minutes Between what two values are the middle 50% of times?

The following stem-and-leaf display shows the number of homeless cats and dogs that had to be euthanized each year in a large city for the period 1985-2004.Use both the stemplot and timeplot to describe the distribution.

The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below.

The weekly salaries (in dollars)of sixteen government workers are listed below.

Here are the highest temperatures ever recorded (in °F)in 32 different states in the U.S.A. Choose the boxplot that represents the given data. I II III IV V

The test scores of 15 students are listed below.

The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below. Choose the boxplot that represents the given data. I II III IV V

Use the high closing values of Naristar Inc.stock from the years 1990 - 2001 to construct a timeplot.

Shown below are the boxplot,the histogram and summary statistics for the weights (in pounds)of 30 newborn babies: Write a few sentences describing the distribution.

Here are summary statistics for the time,in minutes,it took for 20 people to complete an information survey at a walk-in medical clinic. Would you describe this distribution as symmetric or skewed?

The normal monthly precipitation (in inches)for August is listed for 20 different cities in the U.S.A.. Choose the boxplot that represents the given data. I II III IV V

Here are 3 boxplots of weekly gas prices at a service station in the U.S.A.(price in $ per gallon).Compare the distribution of prices over the three years.

Here are boxplots of the points scored during the first 10 games of the basketball season for both Caroline and Alexandra.The coach can take only one player to the state championship.Which one should she take knowing that she would like a safe player?

The weekly salaries (in dollars)of 24 randomly selected employees of a company are shown below,and displayed on the following boxplot. Find the IQR and the standard deviation.Which is the most appropriate measure of spread?

Use the high closing values of Naristar Inc.stock from the years 1992 - 2003 to construct a timeplot.

Shown below are the boxplot and summary statistics for the heights,in centimetres,of a class of Grade 3 students in Halifax,NS. Which measures of centre and spread would you use for this distribution?

Data

Displaying and Describing Categorical Data

Displaying and Summarizing Quantitative Data

The Standard Deviation As a Ruler and the Normal Model

Scatterplots, association, and Correlation

Linear Regression

Regression Wisdom

Re-Expressing Data: Get It Straight

Understanding Randomness

Sample Surveys

Experiments and Observational Surveys

From Randomness to Probability

Probability Rules

Random Variables

Probability Models

Sampling Distribution Models

Confidence Intervals for Proportions

Testing Hypotheses About Proportions

More About Tests

Comparing Two Proportions

Inferences About Means

Comparing Means

Paired Samples and Blocks

Comparing Counts

Inferences for Regression

Analysis of Variance

Multifactor Analysis of Variance

Multiple Regression

Multiple Regression Wisdom

Rank-Based Nonparametric Tests

The Bootstrap

Filters