Question 1

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.
-

Accepted Answer

C

Question 2

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative.
-The age of a car and its fuel efficiency.

Accepted Answer

Typically, as a car ages, its fuel efficiency tends to decrease due to wear and tear on its parts, suggesting a negative correlation between the age of a car and its fuel efficiency.

Question 3

State whether there is no correlation, a positive correlation, or a negative correlation between the x and y variables. If there is a correlation, state whether it is most likely due to coincidence, a common underlying cause, or a direct cause.
- For a group of students in a statistics class, the scatter diagram compares their test scores (y)and the amount of loose pocket change they have(x).

Accepted Answer

B

Question 4

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.
-

Accepted Answer

The answer of Select the best estimate of the correlation...

Question 5

Solve the problem.
-The table below shows the times (in hours)that seven students spend watching television and using the internet. Construct a scatter diagram for the data and state whether these times have no correlation, a positive correlation, or a negative correlation.

$\begin{array}{l}
\text { Student TV TimeInternet Time }\
\begin{array}{lcc} 
& \text { (hours) } & \text { (hours) } \
\text { Tom } & 9 & 6 \
\text { Dick } & 5 & 4 \
\text { Harry } & 3 & 0 \
\text { Sue } & 8 & 9 \
\text { Betty } & 8 & 10 \
\text { Erin } & 6 & 1 \
\text { Jan } & 7 & 10
\end{array}
\end{array}$

Accepted Answer

The answer of Solve the problem.
-The table below shows the...

Question 6

State whether there is no correlation, a positive correlation, or a negative correlation between the x and y variables. If there is a correlation, state whether it is most likely due to coincidence, a common underlying cause, or a direct cause.
- For several customers at the local bookstore, the scatter diagram compares the weight of their books (y)and the umber of pages in them(x).

Accepted Answer

The answer of State whether there is no correlation, a...

Question 7

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative.
-Rate of pedaling a bicycle and speed of the bicycle

Accepted Answer

The rate of pedaling a bicycle and the speed of the bicycle have a positive correlation because as one increases, so does the other.

Question 8

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative.
-The age of a textbook and how well it is written

Accepted Answer

The age of a textbook and how well it is written are not inherently related; a textbook's quality of writing depends on the author's expertise and style, not its age.

Question 9

Solve the problem.
-The table below shows the legal costs and the profits of a company from 2000 to 2005. Construct a scatter diagram for the data and state whether legal costs and profits for this company have no correlation, a positive correlation, or a negative correlation for this period.

$\begin{array} { c c c } 
& \text { Legal Costs } & \text { Profits } \
\text { Year } & \text { (Millions of \$) } & \text { (Millions of \$) } \
2000 & 9 & 9 \
2001 & 14 & 6 \
2002 & 12 & 8 \
2003 & 11 & 14 \
2004 & 15 & 9 \
2005 & 10 & 15
\end{array}$

Accepted Answer

The answer of Solve the problem.
-The table below shows the...

Question 10

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative.
-Time spent walking and distance covered

Accepted Answer

There is a positive correlation between time spent walking and distance covered because the more time you spend walking, the greater the distance you are likely to cover.

Question 11

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.
-

Accepted Answer

The answer of Select the best estimate of the correlation...

Question 12

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.
-

Accepted Answer

The answer of Select the best estimate of the correlation...

Question 13

Provide an appropriate response.
-Estimate the coordinates of the outlier on the graph.

Accepted Answer

The answer of Provide an appropriate response.
-Estimate the coordinates of...

Question 14

State whether there is no correlation, a positive correlation, or a negative correlation between the x and y variables. If there is a correlation, state whether it is most likely due to coincidence, a common underlying cause, or a direct cause.
- For a group of employees at the local video store, the scatter diagram compares the number of days worked per year (y)and the average number of miles walkedweekly (x).

Accepted Answer

The answer of State whether there is no correlation, a...

Question 15

State whether there is no correlation, a positive correlation, or a negative correlation between the x and y variables. If there is a correlation, state whether it is most likely due to coincidence, a common underlying cause, or a direct cause.
- For a group of English students at the local junior college, the scatter diagram compares the number of correct answers on a test they took(y)and the length of the pencil used to take the test(x).

Accepted Answer

The answer of State whether there is no correlation, a...

Question 16

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative.
-The number of hours one sleeps and the number of hours one is awake

Accepted Answer

There is a negative correlation between the number of hours one sleeps and the number of hours one is awake because as one increases, the other decreases within a 24-hour period.

Question 17

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative.
-The time it takes to read a book and the length of the book

Accepted Answer

The answer of State whether you believe the two variables...

Question 18

Solve the problem.
-The following table gives the total sales (revenue)and profits for 8 retailers. Construct a scatter diagram for thedata and state whether sales and profits for these companies have no correlation, a positive correlation, or a
Negative correlation.

$\begin{array}{l}
\begin{array} { l c c } 
\hline \text { Company } & \begin{array} { c } 
\text { Total Sales } \
\text { (Millions of \$) }
\end{array} & \begin{array} { c } 
\text { Profits } \
\text { (Millions of \$) }
\end{array} \
\hline \text { Adams } & 9.5 & 0.5 \
\text { Browns } & 22.0 & 1.4 \
\text { Clay } & 35.0 & 1.8 \
\text { Donners } & 64.0 & 3.0 \
\text { Esters } & 27.5 & 0.9 \
\text { Framer } & 45.0 & 2.6 \
\text { Gillies } & 15.0 & 0.8 \
\text { Hays } & 57.0 & 2.2 \
\hline
\end{array}\
\end{array}$

Accepted Answer

The answer of Solve the problem.
-The following table gives the...

Question 19

How does the outlier affect the correlation coefficient?.

Accepted Answer

The answer of How does the outlier affect the correlation...

Question 20

Solve the problem.
-The table below shows the sales and profits of a company from 2000 to 2005. Construct a scatter diagram for the data and state whether sales and profits for this company have no correlation, a positive correlation, or a negative correlation for this period.

$\begin{array} { c c c } 
\text { Year } & \text { (Millions of \$) } & \begin{array} { c } 
\text { Profits } \
\text { (Millions of \$) }
\end{array} \
2000 & 7 & 1 \
2001 & 12 & 4 \
2002 & 10 & 2 \
2003 & 9 & 2 \
2004 & 13 & 3 \
2005 & 8 & 0
\end{array}$

Accepted Answer

The answer of Solve the problem.
-The table below shows the...

Quiz 7: Correlation and Causality

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. -

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. -The age of a car and its fuel efficiency.

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. -

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. -Rate of pedaling a bicycle and speed of the bicycle

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. -The age of a textbook and how well it is written

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. -Time spent walking and distance covered

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. -

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. -

Provide an appropriate response. -Estimate the coordinates of the outlier on the graph.

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. -The number of hours one sleeps and the number of hours one is awake

State whether you believe the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. -The time it takes to read a book and the length of the book

How does the outlier affect the correlation coefficient?.