Question 1

The ages of the 21 members of a track and field team are listed below.

Accepted Answer

A) 42 
B) 25 
C) 15,42 
D) 40,42 
E) None 
A) 42 
B) 25 
C) 15,42 
D) 40,42 
E) None D

Question 2

A local ice cream shop hand scoops each of its ice cream cones.The cones vary in weight from 120 grams to 216 grams with a mean of 181 grams and a standard deviation of 34 grams.The quartiles and median weights are 146,244,and 202 grams.
Is the distribution symmetric,skewed to the left,or skewed to the right? Explain.

Accepted Answer

A) Skewed to the left,mean higher than median. 
B) Skewed to the right,mean higher than median. 
C) Symmetric,mean lower than median. 
D) Skewed to the right,mean lower than median. 
E) Skewed to the left,mean lower than median. 
A) Skewed to the left,mean higher than median. 
B) Skewed to the right,mean higher than median. 
C) Symmetric,mean lower than median. 
D) Skewed to the right,mean lower than median. 
E) Skewed to the left,mean lower than median. E

Question 3

Shown below are the histogram and summary statistics for the reading scores of 29 fifth graders.  
 
Which measures of centre and spread would you use for this distribution?

Accepted Answer

A) Mean and standard deviation,because the data is symmetric. 
B) Median and IQR,because the data is skewed to the left. 
C) Mean and standard deviation,because the data is skewed to the left. 
D) Mean and IQR,because the data is skewed to the left. 
E) Median and standard deviation,because the data is skewed to the left. 
A) Mean and standard deviation,because the data is symmetric. 
B) Median and IQR,because the data is skewed to the left. 
C) Mean and standard deviation,because the data is skewed to the left. 
D) Mean and IQR,because the data is skewed to the left. 
E) Median and standard deviation,because the data is skewed to the left. B

Question 4

The frequency table shows the weight,in kilograms,of 130 adults,rounded to the nearest kilogram.

Accepted Answer

A) 60,66,67,70,75 in. 
B) 60,65.5,68,70,75 in. 
C) 60,66,67,71,75 in. 
D) 60,65,68,70,75 in. 
E) 60,65,68,71,75 in. 
A) 60,66,67,70,75 in. 
B) 60,65.5,68,70,75 in. 
C) 60,66,67,71,75 in. 
D) 60,65,68,70,75 in. 
E) 60,65,68,71,75 in.

Question 5

The reaction time of 20 drivers at a stop light was measured,in seconds,as the time between the traffic light turning green and the time it took them to press the gas pedal.

Accepted Answer

A) 0.4,7.0 
B) 0.4 
C) 4.2,7.0 
D) 7.0 
E) None 
A) 0.4,7.0 
B) 0.4 
C) 4.2,7.0 
D) 7.0 
E) None

Question 6

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.  
-For which class are the mean and median most different?

Accepted Answer

A) Class 2,because the shape is symmetric. 
B) Class 2,because the shape is skewed to the right. 
C) Class 1,because the shape is skewed to the left. 
D) Class 3,because the shape is symmetric. 
E) Class 2,because the shape is skewed to the left. 
A) Class 2,because the shape is symmetric. 
B) Class 2,because the shape is skewed to the right. 
C) Class 1,because the shape is skewed to the left. 
D) Class 3,because the shape is symmetric. 
E) Class 2,because the shape is skewed to the left.

Question 7

Here is a histogram of the assets (in millions of dollars)of 71 companies.What aspect of this distribution makes it difficult to summarize,or to discuss,the centre and spread? What could be done with these data to make it easier to discuss the distribution?

Accepted Answer

A) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4000 dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or square roots might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
B) The distribution of assets of the 71 companies is heavily skewed to the left.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4 billion dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or square roots might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
C) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4 billion dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or squares might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
D) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4000 dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or squares might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
E) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4 billion dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or square roots might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
A) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4000 dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or square roots might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
B) The distribution of assets of the 71 companies is heavily skewed to the left.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4 billion dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or square roots might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
C) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4 billion dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or squares might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
D) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4000 dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or squares might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible. 
E) The distribution of assets of the 71 companies is heavily skewed to the right.The vast majority of the companies have assets represented in the first bar of the histogram,0 to 4 billion dollars.This makes the discussion of the distribution meaningless.Re-expressing these data using logs or square roots might make the distribution nearly symmetric,and a meaningful discussion of centre and spread might be possible.

Question 8

Shown below are the histogram and summary statistics for the weekly salaries (in dollars)of 24 randomly selected employees of a company:  
Choose the boxplot that represents the given data.

Accepted Answer

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

Question 9

The histograms show the cost of living,in dollars,for 32 Canadian cities.The histogram on the left shows the cost of living for the 32 cities using bins $10 wide,and the histogram on the right displays the same data using bins that are $6 wide.  
Compare the distributions (shape,centre,spread,unusual features).

Accepted Answer

A) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram appears bimodal,with many cities costing just under $104 and another smaller cluster around $119.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
B) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram is unimodal and symmetric.The distribution is centred around $104,and spread out,with values ranging from $86 to $140.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
C) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the left.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram appears bimodal,with many cities costing just under $104 and another smaller cluster around $119.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
D) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram is also unimodal and skewed to the right.The distribution is centred around $104,and spread out,with values ranging from $86 to $140.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
E) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram appears bimodal,with many cities costing just under $104 and another smaller cluster around $119. 
A) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram appears bimodal,with many cities costing just under $104 and another smaller cluster around $119.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
B) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram is unimodal and symmetric.The distribution is centred around $104,and spread out,with values ranging from $86 to $140.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
C) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the left.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram appears bimodal,with many cities costing just under $104 and another smaller cluster around $119.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
D) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram is also unimodal and skewed to the right.The distribution is centred around $104,and spread out,with values ranging from $86 to $140.There also appears to be an outlier in the right histogram at $134 that was not apparent in the histogram on the left. 
E) The distribution in the left histogram of the cost of living in the 32 Canadian cities is unimodal and skewed to the right.The distribution is centred around $100,and spread out,with values ranging from $80 to $140.The distribution in the right histogram appears bimodal,with many cities costing just under $104 and another smaller cluster around $119.

Question 10

Here are the summary statistics for the monthly payroll for an accounting firm:
Lowest salary = $15,000
Mean salary = $35,000
Median = $25,000
Range = $60,000
IQR = $30,000
First quartile = $17,500
Standard deviation = $20,000
Do you think the distribution of salaries is symmetric,skewed to the left,or skewed to the right? Explain why.

Accepted Answer

A) Skewed to the left;mean is lower than median. 
B) Skewed to the right;mean is higher than median. 
C) Symmetric,mean is higher than median. 
D) Skewed to the left,mean is higher than median. 
E) Skewed to the right,mean is lower than median. 
A) Skewed to the left;mean is lower than median. 
B) Skewed to the right;mean is higher than median. 
C) Symmetric,mean is higher than median. 
D) Skewed to the left,mean is higher than median. 
E) Skewed to the right,mean is lower than median.

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.  
Would you use the median or the mean to describe the centre of this distribution?

Accepted Answer

A) Mean,because the data are skewed to the right. 
B) Mean,because the data are skewed to the left. 
C) Mean,because the data are symmetric. 
D) Median,because the data are skewed to the right. 
E) Median,because the data are skewed to the left. 
A) Mean,because the data are skewed to the right. 
B) Mean,because the data are skewed to the left. 
C) Mean,because the data are symmetric. 
D) Median,because the data are skewed to the right. 
E) Median,because the data are skewed to the left.

Question 12

The back-to-back stem-and-leaf display compares the percent growth in sales for a retail chain's stores located in two regions of Canada.The lower stem contains leaves with the digits 0-4 and the upper stem contains leaves with digits 5-9.  
Key:
3 | 5 = 35% sales growth

Accepted Answer

A) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 35% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 15% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 2 stores were higher and more variable than the rates in the Region 1 stores. 
B) The distribution of sales growth in the Region 1 stores is unimodal,symmetric and tightly clustered around 35% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 15% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 1 stores were higher and less variable than the rates in the Region 2 stores. 
C) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 35% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 15% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 1 stores were higher and more variable than the rates in the Region 2 stores. 
D) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 45% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 25% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 2 stores were higher and more variable than the rates in the Region 1 stores. 
E) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 45% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 25% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 1 stores were higher and less variable than the rates in the Region 2 stores. 
A) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 35% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 15% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 2 stores were higher and more variable than the rates in the Region 1 stores. 
B) The distribution of sales growth in the Region 1 stores is unimodal,symmetric and tightly clustered around 35% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 15% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 1 stores were higher and less variable than the rates in the Region 2 stores. 
C) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 35% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 15% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 1 stores were higher and more variable than the rates in the Region 2 stores. 
D) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 45% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 25% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 2 stores were higher and more variable than the rates in the Region 1 stores. 
E) The distribution of sales growth in Region 1 stores is unimodal,symmetric and tightly clustered around 45% growth.The distribution of sales growth in Region 2 stores is much more spread out,with most stores having sales growth between 5% and 35%.A typical Region 2 store had about 25% growth.There were two outliers,one store with 58% growth and another with 65% growth.Generally,the sales growth rates in the Region 1 stores were higher and less variable than the rates in the Region 2 stores.

Question 13

Here are summary statistics of the last four digits of the credit card number of 500 customers,corresponding to the following histogram.  
 
Is the mean or median a "better" summary of the centre of the distribution?

Accepted Answer

A) Median,because the IQR is smaller than the standard deviation. 
B) Median,because of the outliers. 
C) Mean,because the distribution is quite symmetric. 
D) Neither,because these are not categorical data. 
E) Neither,because these are not quantitative data. 
A) Median,because the IQR is smaller than the standard deviation. 
B) Median,because of the outliers. 
C) Mean,because the distribution is quite symmetric. 
D) Neither,because these are not categorical data. 
E) Neither,because these are not quantitative data.

Question 14

The boxplots display case prices (in dollars)of white wines produced by three vineyards in south-western Ontario.Which vineyard produces the cheapest wine?

Accepted Answer

A) Vineyard C,because it has the smallest range. 
B) Vineyard B,because it does not have any outliers. 
C) Vineyard C,because it has the smallest IQR. 
D) Vineyard B,because it has the highest case price at about $150. 
E) Vineyard A,because it has the smallest case price at about $60. 
A) Vineyard C,because it has the smallest range. 
B) Vineyard B,because it does not have any outliers. 
C) Vineyard C,because it has the smallest IQR. 
D) Vineyard B,because it has the highest case price at about $150. 
E) Vineyard A,because it has the smallest case price at about $60.

Question 15

Shown below are the boxplot,the histogram and summary statistics for the weekly salaries (in dollars)of 24 randomly selected employees of a company:  
 
Write a few sentences describing the distribution.

Accepted Answer

A) The distribution is unimodal and skewed to the right.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 978.8,while the mean was 705,above the median score.The middle 50% of the weekly salaries were between $510 and $1225 for an IQR of $715. 
B) The distribution is bimodal and skewed to the right.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $705 and $1225 for an IQR of $520. 
C) The distribution is unimodal and skewed to the left.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $705 and $1225 for an IQR of $520. 
D) The distribution is unimodal and skewed to the right.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $510 and $1225 for an IQR of $715. 
E) The distribution is unimodal and skewed to the left.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $510 and $1225 for an IQR of $715. 
A) The distribution is unimodal and skewed to the right.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 978.8,while the mean was 705,above the median score.The middle 50% of the weekly salaries were between $510 and $1225 for an IQR of $715. 
B) The distribution is bimodal and skewed to the right.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $705 and $1225 for an IQR of $520. 
C) The distribution is unimodal and skewed to the left.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $705 and $1225 for an IQR of $520. 
D) The distribution is unimodal and skewed to the right.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $510 and $1225 for an IQR of $715. 
E) The distribution is unimodal and skewed to the left.As shown in the boxplot,there are two outliers,weekly salaries of $2500 and about $3700.The median was 705,while the mean was 978.8,above the median score.The middle 50% of the weekly salaries were between $510 and $1225 for an IQR of $715.

Question 16

The speed vehicles travelled on a local road was recorded for one month.The speeds ranged from 52 km/h to 67 km/h with a mean speed of 56 km/h and a standard deviation of 7 km/h.The quartiles and median speeds were 55 km/h,64 km/h,and 53 km/h.Suppose during the month,one driver was clocked at 25 km/h.
Which of the summary statistics might not change if that data value was added to the distribution?

Accepted Answer

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

Question 17

Here are summary statistics for the time,in minutes,it took 21 students to write a statistics test.  
Would you describe this distribution as symmetric or skewed?

Accepted Answer

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

Question 18

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 mean score?

Accepted Answer

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

Question 19

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.  
Key:
87 | 5 = 87,500 cats and dogs euthanized

Accepted Answer

A) The distribution of the number of cats and dogs that were euthanized is skewed to the right,with a centre at around 85,500.The number of cats and dogs euthanized each year ranges from 81,000 to 90,100. 
B) 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 89,500.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000. 
C) 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. 
D) The distribution of the number of cats and dogs that were euthanized is unimodal,ranging from 81,000 to 90,100 euthanized.The centre of the distribution is at around 85,500. 
E) 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 88,500.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000. 
A) The distribution of the number of cats and dogs that were euthanized is skewed to the right,with a centre at around 85,500.The number of cats and dogs euthanized each year ranges from 81,000 to 90,100. 
B) 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 89,500.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000. 
C) 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. 
D) The distribution of the number of cats and dogs that were euthanized is unimodal,ranging from 81,000 to 90,100 euthanized.The centre of the distribution is at around 85,500. 
E) 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 88,500.The lower cluster is between 81,000 and 82,000 euthanized,with a centre at around 81,000.

Question 20

A business owner recorded her annual profits for the first 12 years since opening her business.The stem-and-leaf display below shows the annual profits in thousands of dollars.  
Key:
9 | 8 = $98,000 profit

Accepted Answer

A) The distribution of the business owner's profits is skewed to the left,and is multimodal,with gaps in between.Five years the business had profits near $90,000,another four years the business had profits near $60,000,and three years the business had profits near $30,000. 
B) The distribution of the business owner's profits is skewed to the left,and is multimodal,with gaps in between.Five years the business had profits near $100,000,another four years the business had profits near $70,000,and three years the business had profits near $40,000. 
C) The distribution of the business owner's profits is skewed to the right,and is unimodal,with gaps in between.The centre is at around $70,000. 
D) The distribution of the business owner's profits is skewed to the right,and is multimodal,with gaps in between.Five years the business had profits near $100,000,another four years the business had profits near $70,000,and three years the business had profits near $40,000. 
E) The distribution of the business owner's profits is skewed to the left,and is unimodal,with gaps in between.The centre is at around $70,000. 
A) The distribution of the business owner's profits is skewed to the left,and is multimodal,with gaps in between.Five years the business had profits near $90,000,another four years the business had profits near $60,000,and three years the business had profits near $30,000. 
B) The distribution of the business owner's profits is skewed to the left,and is multimodal,with gaps in between.Five years the business had profits near $100,000,another four years the business had profits near $70,000,and three years the business had profits near $40,000. 
C) The distribution of the business owner's profits is skewed to the right,and is unimodal,with gaps in between.The centre is at around $70,000. 
D) The distribution of the business owner's profits is skewed to the right,and is multimodal,with gaps in between.Five years the business had profits near $100,000,another four years the business had profits near $70,000,and three years the business had profits near $40,000. 
E) The distribution of the business owner's profits is skewed to the left,and is unimodal,with gaps in between.The centre is at around $70,000.

Exam 4: Understanding and Comparing Distributions

The ages of the 21 members of a track and field team are listed below.

Shown below are the histogram and summary statistics for the reading scores of 29 fifth graders. Which measures of centre and spread would you use for this distribution?

The frequency table shows the weight,in kilograms,of 130 adults,rounded to the nearest kilogram.

The reaction time of 20 drivers at a stop light was measured,in seconds,as the time between the traffic light turning green and the time it took them to press the gas pedal.

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. -For which class are the mean and median most different?

Here is a histogram of the assets (in millions of dollars)of 71 companies.What aspect of this distribution makes it difficult to summarize,or to discuss,the centre and spread? What could be done with these data to make it easier to discuss the distribution?

Shown below are the histogram and summary statistics for the weekly salaries (in dollars)of 24 randomly selected employees of a company: Choose the boxplot that represents the given data.

Office workers were asked how long it took them,in minutes,to travel to work one morning.Here is the stem-and-leaf display. Would you use the median or the mean to describe the centre of this distribution?

The back-to-back stem-and-leaf display compares the percent growth in sales for a retail chain's stores located in two regions of Canada.The lower stem contains leaves with the digits 0-4 and the upper stem contains leaves with digits 5-9. Key: 3 | 5 = 35% sales growth

Here are summary statistics of the last four digits of the credit card number of 500 customers,corresponding to the following histogram. Is the mean or median a "better" summary of the centre of the distribution?

The boxplots display case prices (in dollars)of white wines produced by three vineyards in south-western Ontario.Which vineyard produces the cheapest wine?

Shown below are the boxplot,the histogram and summary statistics for the weekly salaries (in dollars)of 24 randomly selected employees of a company: Write a few sentences describing the distribution.

Here are summary statistics for the time,in minutes,it took 21 students to write a statistics test. Would you describe this distribution as symmetric or skewed?

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 mean score?

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. Key: 87 | 5 = 87,500 cats and dogs euthanized

A business owner recorded her annual profits for the first 12 years since opening her business.The stem-and-leaf display below shows the annual profits in thousands of dollars. Key: 9 | 8 = $98,000 profit

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