Chapter 3.1, Problem 1E

a.

To determine

To find: The explanatory and the response variable.

Explanation of Solution

Given:

The provided variables are, “The weight gain of corals in aquariums and the temperature of water is controlled at various levels”

Here, the explanatory variable is the water temperature and the response variable is the weight gain. Because the weight gain depends on the temperature of water.

b.

To determine

To find: The explanatory and response variable.

Explanation of Solution

Given:

The provided variables are, “the number of sent text messages and phone calls made to the sample of 100 students.

Here, both the variables could either be explanatory variables or the response variables. Because both the variables are not related to each other. Thus, these could be response or explanatory variables both.