Chapter 1.1, Problem 1.21E

a)

To determine

To identify whether the observational study or experimental study.

Answer to Problem 1.21E

This is an experimental study.

Explanation of Solution

Given:

Is there a relationship between physical fitness and leadership ability? To answer this question, researchers recruit 100 students who are willing to take part in an exercise program. The volunteers are divided into a low-fitness group and a high-fitness group on the basis of a physical examination. All students then take a test designed to measure leadership, and the results for the two groups are compared.

First need to understand about the experimental study and observational study:

Experimental study: Assigning people or things to groups and applying some treatment to one group, while the other group does not receive the treatment.

Observation study: In an observational study, measure or survey members of a sample without trying to affect them.

This study is an experimental study. The volunteers are divided into two groups and given a different treatment to other group.

b)

To determine

To find the population and variables.

Answer to Problem 1.21E

The population is all people in the world and variables are High/low fitness group and leadership.

Explanation of Solution

Given:

Is there a relationship between physical fitness and leadership ability? To answer this question, researchers recruit 100 students who are willing to take part in an exercise program. The volunteers are divided into a low-fitness group and a high-fitness group on the basis of a physical examination. All students then take a test designed to measure leadership, and the results for the two groups are compared.

First need to understand about sample and population.

Population: It is the set of all the possible individuals possessing the characteristic of interest in a study.

Sample: it is the subset of population on which, the actual study performed and from which, the necessary measurements are taken.

The population is all people in the world. The variables are High/low fitness group and leadership.

c)

To determine

To explain why we prefer sample survey

Explanation of Solution

Given:

Is there a relationship between physical fitness and leadership ability? To answer this question, researchers recruit 100 students who are willing to take part in an exercise program. The volunteers are divided into a low-fitness group and a high-fitness group on the basis of a physical examination. All students then take a test designed to measure leadership, and the results for the two groups are compared.

Because the students who volunteer for a fitness program are more interested in sports rather than general population. Hence, sample survey would help to choose such a sample.