Question

Cell phone production engineers have noticed that among a group of 138 customers aged 14-23 who send more text messages tend to use a higher percentage of their phone’s memory.

What are the explanatory variable and response variable for this relationship?
Explanatory variable: age of customer
Response variable: percentage of phone memory used
Explanatory variable: percentage of phone memory used
Response variable: age of customer
Explanatory variable: number of text messages sent
Response variable: percentage of phone memory used
Explanatory variable: percentage of phone memory used
Response variable: number of text messages sent

Answer 1

The explanatory variable is the variable that is manipulated or changed by the researcher, and the response variable is the variable that is measured or observed as a result of the change.

In this case, the explanatory variable is the number of text messages sent by the customers, and the response variable is the percentage of phone memory used by the customers. The engineers are interested in how the number of text messages affects the phone memory usage.

The other options are incorrect because they either reverse the roles of the explanatory and response variables, or they use variables that are not relevant to the relationship under study.