Chapter 12, Problem 19E

(a)

To determine

To find out what kind of design have you used.

Answer to Problem 19E

Cluster sampling design is used.

Explanation of Solution

In the question it is given that for the political science class, they like to take a survey from a sample of all catholic church members in the city. Rather than to try to obtain a list of all members of all these churches, they decided to pick three churches at random. Thus, the kind of sampling used in this study is cluster sampling design because we are randomly selecting three churches out of a whole group and then performing a simple random sample on those three churches.

(b)

To determine

To explain what could go wrong with your design.

Explanation of Solution

In the question it is given that for the political science class, they like to take a survey from a sample of all catholic church members in the city. Rather than to try to obtain a list of all members of all these churches, they decided to pick three churches at random. Thus, the kind of sampling used in this study is cluster sampling design. Thus, with this sampling design it may affect as some churches may not have $100$ people and having a sample size not great enough could increase bias and variability in the data.