Question 1

How would you describe the shape of each distribution?

Accepted Answer

A) Class1: left-skewed,spread out ranging from about 40 to 90
Class 2: left-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
B) Class1: fairly symmetric,spread out ranging from about 40 to 90
Class 2: left-skewed,spread out ranging from about 40 to 90
Class 3: asymmetric,spread out ranging from about 40 to 90 
C) Class1: left-skewed,spread out ranging from about 40 to 90
Class 2: right-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
D) Class1: fairly symmetric,spread out ranging from about 40 to 90
Class 2: left-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
E) Class1: fairly symmetric,spread out ranging from about 40 to 90
Class 2: right-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
A) Class1: left-skewed,spread out ranging from about 40 to 90
Class 2: left-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
B) Class1: fairly symmetric,spread out ranging from about 40 to 90
Class 2: left-skewed,spread out ranging from about 40 to 90
Class 3: asymmetric,spread out ranging from about 40 to 90 
C) Class1: left-skewed,spread out ranging from about 40 to 90
Class 2: right-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
D) Class1: fairly symmetric,spread out ranging from about 40 to 90
Class 2: left-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90 
E) Class1: fairly symmetric,spread out ranging from about 40 to 90
Class 2: right-skewed,spread out ranging from about 40 to 90
Class 3: symmetric,spread out ranging from about 40 to 90

Question 2

Here is the stem-and-leaf display of the midterm test scores for the seventh-period mathematics class.
Midterm Test Scores  
Key:
7 | 5 = 75 points

Accepted Answer

A) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first score is an outlier. 
B) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first two scores are outliers. 
C) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 79 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first two scores are outliers. 
D) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).There are no outliers. 
E) The distribution of the midterm test scores is unimodal and skewed to the right.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first two scores are outliers. 
A) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first score is an outlier. 
B) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first two scores are outliers. 
C) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 79 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first two scores are outliers. 
D) The distribution of the midterm test scores is unimodal and skewed to the left.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).There are no outliers. 
E) The distribution of the midterm test scores is unimodal and skewed to the right.The median is 80 with an IQR of 17 (Q1 is 68 and Q3 is 85).The first two scores are outliers.

Question 3

Match each class with the corresponding boxplot below.

Accepted Answer

A) Class 1 is B
Class 2 is C
Class 3 is A 
B) Class 1 is B
Class 2 is A
Class 3 is C 
C) Class 1 is A
Class 2 is B
Class 3 is C 
D) Class 1 is C
Class 2 is A
Class 3 is B 
E) Class 1 is C
Class 2 is B
Class 3 is A 
A) Class 1 is B
Class 2 is C
Class 3 is A 
B) Class 1 is B
Class 2 is A
Class 3 is C 
C) Class 1 is A
Class 2 is B
Class 3 is C 
D) Class 1 is C
Class 2 is A
Class 3 is B 
E) Class 1 is C
Class 2 is B
Class 3 is A

Question 4

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.  
Write a few sentences about the amount of time these people took to complete the information survey.

Accepted Answer

A) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.8 minutes.The distribution is skewed to the right,with at least the outlier 0.4 minutes. 
B) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.23 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.45 minutes.The distribution is skewed to the right,with at least the outlier 7 minutes. 
C) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.8 minutes.The distribution is skewed to the right,with no outliers. 
D) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 0.4 and 3.8 minutes.The distribution is skewed to the left,with at least the outlier 0.4 minutes. 
E) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.8 minutes.The distribution is skewed to the left,with at least the outlier 7 minutes. 
A) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.8 minutes.The distribution is skewed to the right,with at least the outlier 0.4 minutes. 
B) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.23 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.45 minutes.The distribution is skewed to the right,with at least the outlier 7 minutes. 
C) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.8 minutes.The distribution is skewed to the right,with no outliers. 
D) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 0.4 and 3.8 minutes.The distribution is skewed to the left,with at least the outlier 0.4 minutes. 
E) The 20 times range in length between 0.4 and 7 minutes.The median time is 3.45 minutes,so half are longer and half are shorter.The middle 50% of these times range between 2.1 and 3.8 minutes.The distribution is skewed to the left,with at least the outlier 7 minutes.

Question 5

The weights (in kilograms)of 27 dogs are listed below.

Accepted Answer

A) 1.2,4.2 
B) 3.6,4.2 
C) 1.2,2.0 
D) 1.2,3.6,4.2 
E) None 
A) 1.2,4.2 
B) 3.6,4.2 
C) 1.2,2.0 
D) 1.2,3.6,4.2 
E) None

Question 6

Here are the summary statistics for mathematics scores for one high-school graduating class.  
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

Shown below are the data and summary statistics for the reading scores of 29 fifth graders.  
 
Write a brief summary of the performance of the fifth graders.

Accepted Answer

A) The distribution is unimodal and skewed to the left.The median is 4.6,while the mean is 4.2,lower than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
B) The distribution is unimodal and skewed to the right.The median is 4.6,while the mean is 4.2,lower than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
C) The distribution is unimodal and skewed to the left.The median is 4.6,while the mean is 4.2,lower than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.The score of 1.3 is an outlier. 
D) The distribution is skewed to the right.The median is 4.2,while the mean is 4.6,higher than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
E) The distribution is unimodal and skewed to the left.The median is 4.2,while the mean is 4.6,higher than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
A) The distribution is unimodal and skewed to the left.The median is 4.6,while the mean is 4.2,lower than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
B) The distribution is unimodal and skewed to the right.The median is 4.6,while the mean is 4.2,lower than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
C) The distribution is unimodal and skewed to the left.The median is 4.6,while the mean is 4.2,lower than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.The score of 1.3 is an outlier. 
D) The distribution is skewed to the right.The median is 4.2,while the mean is 4.6,higher than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers. 
E) The distribution is unimodal and skewed to the left.The median is 4.2,while the mean is 4.6,higher than the median score.The middle 50% of the weekly salaries are between 3.6 and 5.2,for an IQR of 1.6.There are no outliers.

Question 8

In a child psychology course,children took part in an experiment to determine how,while putting together a 10-piece puzzle,being able to view the completed picture affected the time required for the child to complete the puzzle.One group (NV)was not allowed to look at the picture on the cover of the puzzle box.A second group (VP)was allowed to view the picture on the cover of the box.Below are the boxplots of the original completion times and the boxplots of the log of the completion times.   
   
Is it better to analyze the original completion times or the log of the completion times? Explain.

Accepted Answer

Answers may vary.One possible opinion is

Question 9

Here are boxplots of the points scored during the first 10 games of the basketball season for both Caroline and Alexandra.Summarize the similarities and differences in their performance so far.

Accepted Answer

A) Both girls have a median score of about 18 points per game.Alexandra is much more consistent,because her IQR is about 15 points,while Caroline's is over 3. 
B) The girls have a different average score per game,but the same median score of about 18 points per game.Their IQR are different,but this does not give anymore information on the girls' performance. 
C) Both girls have a median score of about 18 points per game.Caroline is much more consistent,because her IQR is about 6 points,while Alexandra's is over 20. 
D) The girls have a different average score per game.Caroline is much more consistent,because her IQR is about 4 points,while Alexandra's is over 15. 
E) Both girls have a median score of about 18 points per game.Caroline is much more consistent,because her IQR is about 4 points,while Alexandra's is over 15. 
A) Both girls have a median score of about 18 points per game.Alexandra is much more consistent,because her IQR is about 15 points,while Caroline's is over 3. 
B) The girls have a different average score per game,but the same median score of about 18 points per game.Their IQR are different,but this does not give anymore information on the girls' performance. 
C) Both girls have a median score of about 18 points per game.Caroline is much more consistent,because her IQR is about 6 points,while Alexandra's is over 20. 
D) The girls have a different average score per game.Caroline is much more consistent,because her IQR is about 4 points,while Alexandra's is over 15. 
E) Both girls have a median score of about 18 points per game.Caroline is much more consistent,because her IQR is about 4 points,while Alexandra's is over 15.

Question 10

The normal annual precipitation (in millimetres)is given below for 21 different cities.

Accepted Answer

A) 5.1,13.650,22.0,30.500,51.7 in. 
B) 5.1,14.00,21.05,32.90,51.7 in. 
C) 5.1,14.7,22.0,31.4,51.7 in. 
D) 5.1,13.650,21.05,30.500,51.7 in. 
A) 5.1,13.650,22.0,30.500,51.7 in. 
B) 5.1,14.00,21.05,32.90,51.7 in. 
C) 5.1,14.7,22.0,31.4,51.7 in. 
D) 5.1,13.650,21.05,30.500,51.7 in.

Question 11

Office workers were asked how long it took them,in minutes,to travel to work one morning.Here is the stem-and-leaf display.  
Without actually finding the mean and the median,would you expect the mean to be higher or lower than the median?

Accepted Answer

A) Lower,because the data are skewed to the left. 
B) Higher,because the data are skewed to the left. 
C) Lower,because the data are skewed to the right. 
D) Higher,because the data are skewed to the right. 
E) Neither,because the mean would be equal to the median. 
A) Lower,because the data are skewed to the left. 
B) Higher,because the data are skewed to the left. 
C) Lower,because the data are skewed to the right. 
D) Higher,because the data are skewed to the right. 
E) Neither,because the mean would be equal to the median.

Question 12

Here are the summary statistics for mathematics scores for one high school graduating class,and the parallel boxplots comparing the scores of male and female students.Write a brief report on these results.Be sure to discuss shape,centre,and spread of the scores.

Accepted Answer

A) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a larger range from 30 to 100.The distribution is right-skewed for the females and symmetric for the males. 
B) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a larger range from 30 to 100.Both distributions are right-skewed. 
C) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a larger range from 30 to 100.The distribution is right-skewed for the males and symmetric for the females. 
D) Median score by females at 66 points is 3 points higher than that by males,and male mean is higher by 5.The middle 50% for both group is close with a IQR at 30 for the males and 26 for the females.The males have a larger range from 30 to 100.The distribution is right-skewed for the males and symmetric for the females. 
E) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a smaller range from 30 to 100.Both distributions are left-skewed. 
A) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a larger range from 30 to 100.The distribution is right-skewed for the females and symmetric for the males. 
B) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a larger range from 30 to 100.Both distributions are right-skewed. 
C) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a larger range from 30 to 100.The distribution is right-skewed for the males and symmetric for the females. 
D) Median score by females at 66 points is 3 points higher than that by males,and male mean is higher by 5.The middle 50% for both group is close with a IQR at 30 for the males and 26 for the females.The males have a larger range from 30 to 100.The distribution is right-skewed for the males and symmetric for the females. 
E) Median score by females at 66 points is 3 points higher than that by males,and female mean is higher by 5.The middle 50% for both group is close with a IQR at 26 for the males and 30 for the females.The males have a smaller range from 30 to 100.Both distributions are left-skewed.

Question 13

The heights,in centimetres,of 18 randomly selected Grade 8 students are given below.

Accepted Answer

A) 114,130.50,150,169.0,202 lb 
B) 114,130.50,152.5,169.0,202 lb 
C) 114,134,152.5,171,202 lb 
D) 114,132.25,150,173.00,202 lb 
A) 114,130.50,150,169.0,202 lb 
B) 114,130.50,152.5,169.0,202 lb 
C) 114,134,152.5,171,202 lb 
D) 114,132.25,150,173.00,202 lb

Question 14

Here are the test scores of 32 students:

Accepted Answer

A) 35 
B) 35,99 
C) 99 
D) 35,95,99 
E) None 
A) 35 
B) 35,99 
C) 99 
D) 35,95,99 
E) None

Question 15

Here are the heights,in centimetres,of 32 Grade 3 students.

Accepted Answer

A) 142 
B) 100 
C) 128,142 
D) 100,142 
E) None 
A) 142 
B) 100 
C) 128,142 
D) 100,142 
E) None

Question 16

The frequency table shows the weight ,in kilograms,of 120 adults,rounded to the nearest kilogram.

Accepted Answer

A) 60,65,67,70,75 in. 
B) 60,65,66,70,75 in. 
C) 60,65,67,71,75 in. 
D) 60,66,67,70,75 in. 
E) 60,65,66,71,75 in. 
A) 60,65,67,70,75 in. 
B) 60,65,66,70,75 in. 
C) 60,65,67,71,75 in. 
D) 60,66,67,70,75 in. 
E) 60,65,66,71,75 in.

Question 17

Three statistics classes (50 students each)took the same test.Shown below are histograms of the scores for the classes.Use the histograms to answer the question.  
-Which class had the highest median score?

Accepted Answer

A) Class 2 
B) Class 1 and class 3 
C) Class 3 
D) Class 1 
E) None,because the classes had the same median. 
A) Class 2 
B) Class 1 and class 3 
C) Class 3 
D) Class 1 
E) None,because the classes had the same median.

Question 18

The stem-and-leaf diagram shows the ages of 17 people at a playground in Halifax,Nova Scotia.  
Key:
3 | 4 = 34 years

Accepted Answer

A) The distribution of the ages of people is skewed to the right,with a typical age between 28 and 73..There are 3 outliers,when a person's age is less than 10. 
B) The distribution of the ages of people is skewed to the right,with a typical age between 33 and 39. 
C) The distribution of the ages of people is skewed to the right,with a typical age between 33 and 39.With the exception of the 3 people with ages less than 10,the ages are between 28 and the maximum 73. 
D) The distribution of the ages of people is skewed to the left,with a typical age between 33 and 39.With the exception of the 3 people with ages less than 10,the ages are between 28 and the maximum 73. 
E) The distribution of the ages of people is skewed to the right,with a typical age between 44 and 56.With the exception of the 3 people with ages less than 10,the ages are between 28 and the maximum 73. 
A) The distribution of the ages of people is skewed to the right,with a typical age between 28 and 73..There are 3 outliers,when a person's age is less than 10. 
B) The distribution of the ages of people is skewed to the right,with a typical age between 33 and 39. 
C) The distribution of the ages of people is skewed to the right,with a typical age between 33 and 39.With the exception of the 3 people with ages less than 10,the ages are between 28 and the maximum 73. 
D) The distribution of the ages of people is skewed to the left,with a typical age between 33 and 39.With the exception of the 3 people with ages less than 10,the ages are between 28 and the maximum 73. 
E) The distribution of the ages of people is skewed to the right,with a typical age between 44 and 56.With the exception of the 3 people with ages less than 10,the ages are between 28 and the maximum 73.

Question 19

Here is a histogram of the assets (in millions of dollars)of 71 companies.The logarithm re-expression of assets is also given.In the logarithm re-expression,what does the value 2.25 actually indicate about the company's assets?

Accepted Answer

A) The company's assets are approximately $180. 
B) The company's assets are approximately $3,300. 
C) The company's assets are approximately $180,000,000. 
D) The company's assets are approximately $330,000. 
E) The company's assets are approximately $180,000. 
A) The company's assets are approximately $180. 
B) The company's assets are approximately $3,300. 
C) The company's assets are approximately $180,000,000. 
D) The company's assets are approximately $330,000. 
E) The company's assets are approximately $180,000.

Question 20

Use the Olympic gold medal performances in the men's high jump from the years 1960 - 1984 to construct a timeplot.

Accepted Answer

The answer of Use the Olympic gold medal performances in...

Exam 4: Understanding and Comparing Distributions

How would you describe the shape of each distribution?

Here is the stem-and-leaf display of the midterm test scores for the seventh-period mathematics class. Midterm Test Scores Key: 7 | 5 = 75 points

Match each class with the corresponding boxplot below.

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. Write a few sentences about the amount of time these people took to complete the information survey.

The weights (in kilograms)of 27 dogs are listed below.

Here are the summary statistics for mathematics scores for one high-school graduating class. Choose the boxplot that represents the given data. I II III IV V

Shown below are the data and summary statistics for the reading scores of 29 fifth graders. Write a brief summary of the performance of the fifth graders.

Here are boxplots of the points scored during the first 10 games of the basketball season for both Caroline and Alexandra.Summarize the similarities and differences in their performance so far.

The normal annual precipitation (in millimetres)is given below for 21 different cities.

Office workers were asked how long it took them,in minutes,to travel to work one morning.Here is the stem-and-leaf display. Without actually finding the mean and the median,would you expect the mean to be higher or lower than the median?

Here are the summary statistics for mathematics scores for one high school graduating class,and the parallel boxplots comparing the scores of male and female students.Write a brief report on these results.Be sure to discuss shape,centre,and spread of the scores.

The heights,in centimetres,of 18 randomly selected Grade 8 students are given below.

Here are the test scores of 32 students:

Here are the heights,in centimetres,of 32 Grade 3 students.

The frequency table shows the weight ,in kilograms,of 120 adults,rounded to the nearest kilogram.

Three statistics classes (50 students each)took the same test.Shown below are histograms of the scores for the classes.Use the histograms to answer the question. -Which class had the highest median score?

The stem-and-leaf diagram shows the ages of 17 people at a playground in Halifax,Nova Scotia. Key: 3 | 4 = 34 years

Here is a histogram of the assets (in millions of dollars)of 71 companies.The logarithm re-expression of assets is also given.In the logarithm re-expression,what does the value 2.25 actually indicate about the company's assets?

Use the Olympic gold medal performances in the men's high jump from the years 1960 - 1984 to construct a timeplot.

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

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