Chapter 5, Problem 25E

a)

To determine

To explain W’s for the data.

Explanation of Solution

Given:

  

Let the general W’s are: Who, what, where, when and how.

We will see one by one.

Who: Volunteers or students.

What: Memory test

Where: Not given.

When: Not given.

Why: To find the effect of caffeine on memory retention.

How: Volunteers took a memory test 2 hours after drinking soda.

b)

To determine

To name variables with their type as categorical or quantitative.

Explanation of Solution

Given:

  

The variables are: Types of soda and Memory test score.

The categorical variable: Types of soda.

The quantitative variable: Memory test score.

c)

To determine

To create a parallel boxplot.

Explanation of Solution

Given:

  

Following is the parallel boxplot:

  

d)

To determine

To explain the three groups.

Explanation of Solution

Given:

  

  

The shape of the distributions of No caffeine and High caffeine are left skewed. The shape of the distribution of Low caffeine is right skewed. The center of the distribution of No and Low caffeine is same. The spread of High caffeine is largest. But the spread of the No caffeine is smallest. There are no outliers represent by the boxplot.