Question 1

If two variables are negatively associated, then above-average values of one tend to accompany:

Accepted Answer

A)  below-average values of the other. 
B)  above-average values of the other. 
C)  oppositely signed values of the other. 
D)  negatively signed values of the other. 
A)  below-average values of the other. 
B)  above-average values of the other. 
C)  oppositely signed values of the other. 
D)  negatively signed values of the other.

Question 2

A computer store purchases advertising time on local television stations. For the variables representing the number of advertisements purchased and the number of computers sold, you would expect:

Accepted Answer

A)  a substantial negative correlation. 
B)  a substantial positive correlation. 
C)  a small correlation. 
D)  no correlation. 
A)  a substantial negative correlation. 
B)  a substantial positive correlation. 
C)  a small correlation. 
D)  no correlation.

Question 3

If the correlation between two variables is 1, then the points of their scatterplot:

Accepted Answer

A)  all lie within 1 unit of the regression line. 
B)  all lie within $\frac{1}{2}$ unit of the regression line. 
C)  all lie on the regression line. 
D)  lie so that exactly half of the points are on each side of the regression line. 
A)  all lie within 1 unit of the regression line. 
B)  all lie within $\frac{1}{2}$ unit of the regression line. 
C)  all lie on the regression line. 
D)  lie so that exactly half of the points are on each side of the regression line.

Question 4

If there is an association between two variables, is it reasonable to presume that changes in one variable will cause changes in the other variable?

Accepted Answer

No. Associ

Question 5

If two variables are both positive, and tend to be linked so that growth of one variable tends to indicate growth in the other variable, then:

Accepted Answer

A)  the variables are positively associated. 
B)  the variables are negatively associated. 
C) the variables have no association with each other. 
D) The association of the variables cannot be determined. 
A)  the variables are positively associated. 
B)  the variables are negatively associated. 
C) the variables have no association with each other. 
D) The association of the variables cannot be determined.

Question 6

When you are interested in the relation between the class size and course evaluation, identify the explanatory variable.

Accepted Answer

The answer of When you are interested in the relation...

Question 7

Use the following data set to answer the  Questions:  $\begin{array} { | l | l | l | l | l | l | l | l | l } 
\hline \begin{array} { l } 
\text { Length of } \
\text { commute in } \
\text { miles } ( x )
\end{array} & 2 & 10 & 8 & 30 & 12 & 70 & 15 & 20 \
\hline \begin{array} { l } 
\text { Time of } \
\text { commute in } \
\text { minutes (y) }
\end{array} & 5 & 25 & 20 & 45 & 25 & 80 & 30 & 35 \
\hline
\end{array}$
-According to the regression equation, what is the expected length in minutes of a 0-mile commute?

Accepted Answer

A)  0 
B)  10 
C)  12 
D)  20 
A)  0 
B)  10 
C)  12 
D)  20

Question 8

If the variables have a negative association, then their correlation:

Accepted Answer

A)  must be less than −1. 
B)  must be between −1 and 0. 
C)  must be between 0 and 1. 
D)  must be greater than 1. 
A)  must be less than −1. 
B)  must be between −1 and 0. 
C)  must be between 0 and 1. 
D)  must be greater than 1.

Question 9

What are two variables associated with professional baseball players that are most likely negatively associated?

Accepted Answer

Answers will vary. F

Question 10

Describe the form, direction, and strength of the relationship below. $$\begin{array} { l c c c c c c c c c c c c } 
\text { Time spent } & 1 & 2 & 5 & 4 & 6 & 7 & 8 & 5 & 2 & 4 & 3 & 5 \
\text { studying (hours) } & & & & & & & & & & & & \
\begin{array} { l } 
\text { Test score } \
\text { (percentage) }
\end{array} & 49 & 57 & 80 & 70 & 88 & 91 & 98 & 80 & 57 & 72 & 65 & 82
\end{array}$$

Accepted Answer

The form is a straight-line pa

Question 11

If the regression line is $y$=-3$x$ + 4 , which of the following must hold true?

Accepted Answer

A)  The variables have a strong correlation. 
B)  The variables have a negative association. 
C)  The scatterplot shows a linear trend. 
D)  All of the above. 
A)  The variables have a strong correlation. 
B)  The variables have a negative association. 
C)  The scatterplot shows a linear trend. 
D)  All of the above.

Question 12

What are two variables associated with professional baseball players that are most likely positively associated?

Accepted Answer

Answers will vary. F

Question 13

When you are interested in the relation between smoking status and death from lung cancer, identify the response variable.

Accepted Answer

The answer of When you are interested in the relation...

Question 14

Suppose the equation for a regression line is y = 18 − 3x. If y = 9, what is the predicted corresponding value for x?

Accepted Answer

The answer of Suppose the equation for a regression line...

Question 15

What is the intercept of the regression line?

Accepted Answer

A)  about 70 
B)  about 48 
C)  about 43 
D)  None of the above. 
A)  about 70 
B)  about 48 
C)  about 43 
D)  None of the above.

Question 16

Use the following scatterplot to answer the  Questions:
 
-What can you say about outliers in the data set?

Accepted Answer

A)  There are no apparent outliers. 
B)  There is only one outlier. 
C)  There are only two outliers. 
D)  There are many outliers. 
A)  There are no apparent outliers. 
B)  There is only one outlier. 
C)  There are only two outliers. 
D)  There are many outliers.

Question 17

Use the following Table to answer the  Questions: $\begin{array} { | l | c | c | c | c | c | c | c | } 
\hline \begin{array} { l } 
\text { Hours spent } \
\text { partying per } \
\text { week } ( x )
\end{array} & 10 & 40 & 0 & 5 & 60 & 20 & 12 \
\hline \text { GPA } ( y ) & 3.4 & 0.5 & 3.9 & 3.7 & 4.0 & 1.3 & 3.1 \
\hline
\end{array}$
-According to the regression equation, what is the expected GPA of a student who parties 30 hours a week?

Accepted Answer

The answer of Use the following Table to answer the...

Question 18

If the least-squares regression line is $y = - 2 x + 17$ then what is the residual for the point (10, 5)?

Accepted Answer

A) -3 
B)  3 
C)  8 
D) -8 
A) -3 
B)  3 
C)  8 
D) -8

Question 19

The slope of the least-squares regression line is:

Accepted Answer

A)  the correlation between the variables. 
B)  the same sign as the correlation between the variables. 
C)  the opposite of the correlation between the variables. 
D)  the opposite sign of the correlation between the variables. 
A)  the correlation between the variables. 
B)  the same sign as the correlation between the variables. 
C)  the opposite of the correlation between the variables. 
D)  the opposite sign of the correlation between the variables.

Question 20

Use the following data set to answer the  Questions:  $\begin{array} { | l | l | l | l | l | l | l | l | l } 
\hline \begin{array} { l } 
\text { Length of } \
\text { commute in } \
\text { miles } ( x )
\end{array} & 2 & 10 & 8 & 30 & 12 & 70 & 15 & 20 \
\hline \begin{array} { l } 
\text { Time of } \
\text { commute in } \
\text { minutes (y) }
\end{array} & 5 & 25 & 20 & 45 & 25 & 80 & 30 & 35 \
\hline
\end{array}$
-According to the regression equation, each additional mile adds, on average, about how many minutes to the commute?

Accepted Answer

A)  0.5 
B)  1 
C)  1.5 
D)  2 
A)  0.5 
B)  1 
C)  1.5 
D)  2

Exam 6: Exploring Data: Relationships

If two variables are negatively associated, then above-average values of one tend to accompany:

A computer store purchases advertising time on local television stations. For the variables representing the number of advertisements purchased and the number of computers sold, you would expect:

If the correlation between two variables is 1, then the points of their scatterplot:

If there is an association between two variables, is it reasonable to presume that changes in one variable will cause changes in the other variable?

If two variables are both positive, and tend to be linked so that growth of one variable tends to indicate growth in the other variable, then:

When you are interested in the relation between the class size and course evaluation, identify the explanatory variable.

Use the following data set to answer the Questions: Length of commute in miles (x) 2 10 8 30 12 70 15 20 Time of commute in minutes (y) 5 25 20 45 25 80 30 35 -According to the regression equation, what is the expected length in minutes of a 0-mile commute?

If the variables have a negative association, then their correlation:

What are two variables associated with professional baseball players that are most likely negatively associated?

Describe the form, direction, and strength of the relationship below. Time spent 1 2 5 4 6 7 8 5 2 4 3 5 studying (hours) Test score (percentage) 49 57 80 70 88 91 98 80 57 72 65 82

If the regression line is yyy =-3 xxx + 4 , which of the following must hold true?

What are two variables associated with professional baseball players that are most likely positively associated?

When you are interested in the relation between smoking status and death from lung cancer, identify the response variable.

Suppose the equation for a regression line is y = 18 − 3x. If y = 9, what is the predicted corresponding value for x?

What is the intercept of the regression line?

Use the following scatterplot to answer the Questions: -What can you say about outliers in the data set?

Use the following Table to answer the Questions: Hours spent partying per week (x) 10 40 0 5 60 20 12 GPA (y) 3.4 0.5 3.9 3.7 4.0 1.3 3.1 -According to the regression equation, what is the expected GPA of a student who parties 30 hours a week?

If the least-squares regression line is y=−2x+17y = - 2 x + 17y=−2x+17 then what is the residual for the point (10, 5)?

The slope of the least-squares regression line is:

Use the following data set to answer the Questions: Length of commute in miles (x) 2 10 8 30 12 70 15 20 Time of commute in minutes (y) 5 25 20 45 25 80 30 35 -According to the regression equation, each additional mile adds, on average, about how many minutes to the commute?

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Exploring Data: Distributions

Data for Decisions

Probability: the Mathematics of Chance

Social Choice: the Impossible Dream

The Manipulability of Voting Systems

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Electing the President

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Game Theory: the Mathematics of Competition

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If the regression line is $y$ =-3 $x$ + 4 , which of the following must hold true?

If the least-squares regression line is $y = - 2 x + 17$ then what is the residual for the point (10, 5)?