Chapter 7, Problem 2E

(a)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same.

Answer to Problem 2E

Price would be the explanatory variable and number sold would be the response variable.

There is a negative, linear relationship. The relationship is strong.

Explanation of Solution

Now, we have to find out for the: T-shirts at a store; price each and number sold.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that, price is the explanatory variable and number sold is the response variable because price predicts the number that will be sold.

The relationship is negative because as price increases, the number sold is expected to decrease. The relationship is linear because as price increases, the number sold is expected to decrease by the same amount each time. The relationship is strong because the relationship between the two is almost entirely linear.

(b)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same

Answer to Problem 2E

Depth would be the explanatory variable and water pressure would be the response variable.

There is a positive, linear relationship. The relationship is strong.

Explanation of Solution

Now, we have to find out for the: Scuba diving; depth and water pressure.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that,depth is the explanatory variable and water pressure is the response variable because depth is used to predict the water pressure.

The relationship is positive because as depth increases, water pressure also increases. The relationship is linear because as depth increases by one unit, water pressure also increases by the same amount each time. The relationship is strong because the relationship between the two is likely almost completely linear.

(c)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same

Answer to Problem 2E

Depth is the explanatory variable and visibility is the response variable.

There is a negative, linear relationship. The relationship is strong.

Explanation of Solution

Now, we have to find out for the: Scuba diving; depth and visibility.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that,depth is the explanatory variable and visibility is the response variable because depth is used to predict visibility.

The relationship is negative because as depth increases, visibility decreases. The relationship is linear because as depth increases by one unit each time, visibility is expected to decrease by the same amount each time. The relationship is strong because the relationship between the two is almost completely linear.

(d)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same

Answer to Problem 2E

Weight is the explanatory variable and score is the response variable.

There is no relationship between the two variables.

Explanation of Solution

Now, we have to find out for the: All elementary school students; weight and a score on a reading test.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that,weight is the explanatory variable and score is the response variable because weight is being used to predict reading score.

There is no relationship because there is no correlation between a child's weight and his/her reading score.