Question 1

All but one of the statements below contain a mistake.Which one could be true?

Accepted Answer

A) If the correlation between blood alcohol level and reaction time is 0.73, then the correlation between reaction time and blood alcohol level is -0.73. 
B) The correlation between the breed of a dog and its weight is 0.435. 
C) The correlation between gender and age is -0.171. 
D) The correlation between height and weight is 0.568 inches per pound. 
E) The correlation between weight and length of foot is 0.488. 
A) If the correlation between blood alcohol level and reaction time is 0.73, then the correlation between reaction time and blood alcohol level is -0.73. 
B) The correlation between the breed of a dog and its weight is 0.435. 
C) The correlation between gender and age is -0.171. 
D) The correlation between height and weight is 0.568 inches per pound. 
E) The correlation between weight and length of foot is 0.488. E

Question 2

A study examined consumption levels of oil and carbon dioxide emissions for sample of counties.The response variable in this study is

Accepted Answer

A) oil. 
B) oil consumption. 
C) carbon dioxide emissions. 
D) countries. 
E) none of the above. 
A) oil. 
B) oil consumption. 
C) carbon dioxide emissions. 
D) countries. 
E) none of the above. C

Question 3

Shown below is a correlation table showing correlation coefficients between stock price, earnings per share (EPS) and price/earnings (P/E) ratio for a sample of 19 publicly traded
Companies.Which of the following statements is false?

Accepted Answer

A) EPS is the best predictor of stock price. 
B) The strongest correlation is between EPS and stock price. 
C) There is a weak negative association between PE and EPS. 
D) PE is the best predictor of stock price. 
E) The weakest correlation is between PE and EPS. 
A) EPS is the best predictor of stock price. 
B) The strongest correlation is between EPS and stock price. 
C) There is a weak negative association between PE and EPS. 
D) PE is the best predictor of stock price. 
E) The weakest correlation is between PE and EPS. D

Question 4

The correlation coefficient between the hours that a person is awake during a 24-hour period and the hours that same person is asleep during a 24-hour period is most likely to be

Accepted Answer

A) near -0.8 
B) exactly -1.0 
C) exactly +1.0 
D) near 0 
E) near +0.8 
A) near -0.8 
B) exactly -1.0 
C) exactly +1.0 
D) near 0 
E) near +0.8

Question 5

For the following scatterplot,   The likely correlation coefficient is

Accepted Answer

A) +0.35 
B) +0.90 
C) +0.77 
D) -0.89 
E) -1.00 
A) +0.35 
B) +0.90 
C) +0.77 
D) -0.89 
E) -1.00

Question 6

A consumer research group examining the relationship between the price of meat (per pound) and fat content (in grams) gathered data that produced the following scatterplot.   If the point in the lower left hand corner (2 grams of fat; $3.00 per pound) is removed, the
Correlation would most likely

Accepted Answer

A) remain the same. 
B) become positive. 
C) become weaker negative. 
D) become stronger negative. 
E) become zero. 
A) remain the same. 
B) become positive. 
C) become weaker negative. 
D) become stronger negative. 
E) become zero.

Question 7

A scatterplot of $\frac { 1 } { \sqrt { y } }$ vs. $x$ shows a strong positive linear pattern. It is probably true that

Accepted Answer

A)  accurate predictions can be made for $\mathrm { Y }$ even if extrapolation is involved. 
B)  the correlation between $\mathrm { X }$ and $\mathrm { Y }$ is near $+ 1.0$. 
C)  large values of $X$ are associated with large values of $Y$. 
D)  the scatterplot of $\mathrm { Y }$ vs $\mathrm { X }$ also shows a linear pattern. 
E)  the residuals plot for regression of $Y$ on $X$ shows a curved pattern. 
A)  accurate predictions can be made for $\mathrm { Y }$ even if extrapolation is involved. 
B)  the correlation between $\mathrm { X }$ and $\mathrm { Y }$ is near $+ 1.0$. 
C)  large values of $X$ are associated with large values of $Y$. 
D)  the scatterplot of $\mathrm { Y }$ vs $\mathrm { X }$ also shows a linear pattern. 
E)  the residuals plot for regression of $Y$ on $X$ shows a curved pattern.

Question 8

A company's sales increase by the same amount each year.This growth is ...

Accepted Answer

A) quadratic 
B) exponential 
C) linear 
D) logarithmic 
E) Power 
A) quadratic 
B) exponential 
C) linear 
D) logarithmic 
E) Power

Question 9

A small independent organic food store offers a variety of specialty coffees.To determine whether price has an impact on sales, the managers kept track of how many pounds of each
Variety of coffee were sold last month.Based on the scatterplot shown below, which of the
Following statements is true?

Accepted Answer

A) The quantitative variable condition is satisfied. 
B) The linearity condition is satisfied. 
C) There are no obvious outliers. 
D) All of the above. 
E) None of the above. 
A) The quantitative variable condition is satisfied. 
B) The linearity condition is satisfied. 
C) There are no obvious outliers. 
D) All of the above. 
E) None of the above.

Question 10

The disadvantage of re-expressing variables is that

Accepted Answer

A) We have to explain the association in terms of the transformed variables. 
B) We cannot use the standard regression models 
C) It is not commonly used 
D) It can be difficult 
E) A and D 
A) We have to explain the association in terms of the transformed variables. 
B) We cannot use the standard regression models 
C) It is not commonly used 
D) It can be difficult 
E) A and D

Question 11

A small independent organic food store offers a variety of specialty coffees.To determine whether price has an impact on sales, the managers kept track of how many pounds of each
Variety of coffee were sold last month.   Based on the scatterplot, the linear relationship between number of pounds of coffee sold per
Week and price is

Accepted Answer

A) strong and positive. 
B) strong and negative. 
C) weak and negative. 
D) weak and positive. 
E) nonexistent. 
A) strong and positive. 
B) strong and negative. 
C) weak and negative. 
D) weak and positive. 
E) nonexistent.

Question 12

The scatterplot shows monthly sales figures (in units) and number of months of experience for a sample of salespeople.   The correlation between monthly sales and level of experience is most likely

Accepted Answer

A) -.235. 
B) 0. 
C) .180. 
D) -.914. 
E) .914. 
A) -.235. 
B) 0. 
C) .180. 
D) -.914. 
E) .914.

Question 13

All but one of the statements below contain a mistake.Which one could be true?

Accepted Answer

A) The correlation between the height of a bean plant and the day is 0.78 in/day. 
B) The correlation between the time it takes to get ready in the morning and gender is 0.78. 
C) The correlation between your golf score and the number of hours you practice is -0.36. 
D) The number of apricots on a tree and the amount of fertilizer have a 1.12 correlation. 
E) There is a strong correlation between type of preferred pet and income level. 
A) The correlation between the height of a bean plant and the day is 0.78 in/day. 
B) The correlation between the time it takes to get ready in the morning and gender is 0.78. 
C) The correlation between your golf score and the number of hours you practice is -0.36. 
D) The number of apricots on a tree and the amount of fertilizer have a 1.12 correlation. 
E) There is a strong correlation between type of preferred pet and income level.

Question 14

A correlation of zero between two quantitative variables means that

Accepted Answer

A) there is no linear association between the two variables. 
B) re-expressing the data will guarantee a linear association between the two variables. 
C) there is no association between the two variables. 
D) we have done something wrong in our calculation of r. 
E) none of these 
A) there is no linear association between the two variables. 
B) re-expressing the data will guarantee a linear association between the two variables. 
C) there is no association between the two variables. 
D) we have done something wrong in our calculation of r. 
E) none of these

Question 15

All but one of these statements contain a mistake.Which could be true?

Accepted Answer

A) The correlation between a car's length and its fuel efficiency is 0.71 miles per gallon. 
B) There is a correlation of 0.63 between gender and political party. 
C) There is a high correlation (1.09) between height of a corn stalk and its age in weeks. 
D) The correlation between the amount of fertilizer used and the yield of beans is 0.42. 
E) The correlation between a football player's weight and the position he plays is 0.54. 
A) The correlation between a car's length and its fuel efficiency is 0.71 miles per gallon. 
B) There is a correlation of 0.63 between gender and political party. 
C) There is a high correlation (1.09) between height of a corn stalk and its age in weeks. 
D) The correlation between the amount of fertilizer used and the yield of beans is 0.42. 
E) The correlation between a football player's weight and the position he plays is 0.54.

Question 16

The correlation between Hours Sleep and Quiz score of the 60 students in your statistics class is r = -0.34.Which of these possible conclusions is justified:

Accepted Answer

A) The more you sleep, the better your quiz score will be. 
B) The form of the relationship between Hours Sleep and Quiz score is moderately straight. 
C) There are several outliers that explain the low correlation. 
D) If we measure Sleep in minutes rather than hours, the correlation will increase. 
E) There exists a moderately stong, negative association between Gours Sleep and Quiz score. 
A) The more you sleep, the better your quiz score will be. 
B) The form of the relationship between Hours Sleep and Quiz score is moderately straight. 
C) There are several outliers that explain the low correlation. 
D) If we measure Sleep in minutes rather than hours, the correlation will increase. 
E) There exists a moderately stong, negative association between Gours Sleep and Quiz score.

Question 17

The scatterplot shows monthly sales figures (in units) and number of months of experience for a sample of salespeople.   The association between monthly sales and level of experience can be described as

Accepted Answer

A) positive and weak. 
B) negative and weak. 
C) negative and strong. 
D) positive and strong. 
A) positive and weak. 
B) negative and weak. 
C) negative and strong. 
D) positive and strong.

Question 18

Another company's sales increase by the same percent each year.This growth is …

Accepted Answer

A) logarithmic 
B) quadratic 
C) linear 
D) exponential 
E) power 
A) logarithmic 
B) quadratic 
C) linear 
D) exponential 
E) power

Question 19

A supermarket chain gathers data on the amount they spend on promotional material (e.g., coupons, etc.) and sales revenue generated each quarter.The predictor variable is

Accepted Answer

A) sales revenue. 
B) amount spent on promotional material. 
C) number of coupons offered. 
D) supermarket chains. 
E) none of the above. 
A) sales revenue. 
B) amount spent on promotional material. 
C) number of coupons offered. 
D) supermarket chains. 
E) none of the above.

Exam 6: Scatterplots, Association, and Correlation

All but one of the statements below contain a mistake.Which one could be true?

A study examined consumption levels of oil and carbon dioxide emissions for sample of counties.The response variable in this study is

Shown below is a correlation table showing correlation coefficients between stock price, earnings per share (EPS) and price/earnings (P/E) ratio for a sample of 19 publicly traded Companies.Which of the following statements is false?

The correlation coefficient between the hours that a person is awake during a 24-hour period and the hours that same person is asleep during a 24-hour period is most likely to be

For the following scatterplot, The likely correlation coefficient is

A consumer research group examining the relationship between the price of meat (per pound) and fat content (in grams) gathered data that produced the following scatterplot. If the point in the lower left hand corner (2 grams of fat; $3.00 per pound) is removed, the Correlation would most likely

A scatterplot of 1y\frac { 1 } { \sqrt { y } }y​1​ vs. xxx shows a strong positive linear pattern. It is probably true that

A company's sales increase by the same amount each year.This growth is ...

A small independent organic food store offers a variety of specialty coffees.To determine whether price has an impact on sales, the managers kept track of how many pounds of each Variety of coffee were sold last month.Based on the scatterplot shown below, which of the Following statements is true?

The disadvantage of re-expressing variables is that

The scatterplot shows monthly sales figures (in units) and number of months of experience for a sample of salespeople. The correlation between monthly sales and level of experience is most likely

All but one of the statements below contain a mistake.Which one could be true?

A correlation of zero between two quantitative variables means that

All but one of these statements contain a mistake.Which could be true?

The correlation between Hours Sleep and Quiz score of the 60 students in your statistics class is r = -0.34.Which of these possible conclusions is justified:

The scatterplot shows monthly sales figures (in units) and number of months of experience for a sample of salespeople. The association between monthly sales and level of experience can be described as

Another company's sales increase by the same percent each year.This growth is …

A supermarket chain gathers data on the amount they spend on promotional material (e.g., coupons, etc.) and sales revenue generated each quarter.The predictor variable is

Stats Starts Here

Displaying and Describing Data

Relationships Between Categorical Variablescontingency Tables

Understanding and Comparing Distributions

The Standard Deviation As a Ruler and the Normal Model

Linear Regression

Regression Wisdom

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From Randomness to Probability

Probability Rules

Random Variables

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Confidence Intervals for Means

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More About Tests and Intervals

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Comparing Counts

Inferences for Regression

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A scatterplot of $\frac { 1 } { \sqrt { y } }$ vs. $x$ shows a strong positive linear pattern. It is probably true that