Chapter 4, Problem 4.15CYS

To determine

To identify: The explanatory variable.

Answer to Problem 4.15CYS

The correct option is (b) engine size.

Explanation of Solution

Given info:

The data set includes the engine size (as measured by engine displacement in liters) and combined city and highway gas mileage (in miles per gallon).

Reason for correct answer:

Here, gas mileage is predicted from engine size. That is, engine size influences the gas mileage. Thus, the gas mileage is the dependent variable and engine size is the explanatory variable. Also, for constructing scatterplot, the x axis represents the explanatory variable.

Thus, for constructing the scatterplot to predict gas mileage fromengine size, the explanatory variable on the x axis engine size.

Hence, the correct option is (b) engine size.

Reason for incorrect answers:

Here, the gas mileage dependent variable. Thus, the option (a)gas mileageis incorrect.

Also, the explanatory variable is takes in x axis in the scatterplot.Thus, the option (c) can be either gas mileage or engine size is incorrect.

Conclusion:

Thus, when constructing a scatterplot, the explanatory variable is on the x axis and it is engine size.

Statistics Concept Introduction

Introduction:

Response variable:

A response variable is the dependent variable which measures a result of a study.

Explanatory variable:

An explanatory variable is the independent variable, which influence the response variable.