Chapter 13, Problem 20E

a)

To determine

To find the type of the study.

Answer to Problem 20E

This is an observational study.

Explanation of Solution

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 is an observational study because the treatment is not imposed on the subjects and results are based on observations.

b)

To determine

To find whether the study is retrospective or prospective.

Answer to Problem 20E

Prospective study.

Explanation of Solution

There are two types of Observational study:

Retrospective: The data are collected from the past by going back in time.

Prospective: The data are collected in the future.

The data collected first and then traits were observed. Therefore, it is prospective study.

c)

To determine

To explain the subjects with their selection.

Answer to Problem 20E

The people in general public.

Explanation of Solution

I this study, the subjects were members of the general public. The selection process is two random sample collected.

d)

To determine

To find the parameter of interest.

Answer to Problem 20E

To identify variables on which there was no difference.

Explanation of Solution

In this study, the parameter of interest is to identify variables on which there was no difference.

e)

To determine

To explain the nature and scope of the conclusion.

Explanation of Solution

The objective of the study would be identifying the difference between the people who reached by ordinary 5-day telephone survey and who cannot reach to survey.