Chapter 4, Problem R4.2RE

(a)

To determine

To give an example of a way to choose a voluntary response sample of students and explain how this method could lead to bias.

Explanation of Solution

In this, the survey is conducted on the opinions about the parking lot from the students.

Since voluntary surveys are generally responded to only by those who feel strongly about the issue, these results will likely be biased. And also use the daily announcement for volunteers to come in at lunch to take the survey.

(b)

To determine

To give an example of a way to choose a convenience sample of students and explain how this method could lead to bias.

Explanation of Solution

In this, the survey is conducted on the opinions about the parking lot from the students.

For example, we could choose the first $50$ students who arrive on the campus parking lot in a day.

This would then create bias because the first $50$ students will most likely have much different opinions about parking on the campus compared to the other students who didn’t find any available spots to park.

(c)

To determine

To describe how to select an SRS of $50$ students from the school.

Explanation of Solution

To select an SRS of $50$ students from the school, we should randomly select the students from the school so that the sample we collect represent the whole school. That is, the sample’s survey will describe the result of the whole school. In this way the result will not be biased and also it will be accurate.

(d)

To determine

To explain how this method you described in part (c) avoids the biases you described in part (a) and (b).

Explanation of Solution

The method you described in part (c) avoids the biases you described in part (a) and (b) as in this method the students are selected at random so that the sample we collect represent the whole school. That is, the sample’s survey will describe the result of the whole school. In this way the result will not be biased and also it will be accurate.