Question 14.3: Selecting Students Using the population of 20 students shown......

Step 1 Divide the population into two subgroups, consisting of males and females, as shown in Figure 14-6.

Step 2 Divide each subgroup further into two groups of freshmen and sophomores, as shown in Figure 14-7.

Step 3 Determine how many students need to be selected from each subgroup to have a proportional representation of each subgroup in the sample. There are four groups, and since a total of eight students is needed for the sample, two students must be selected from each subgroup.

Step 4 Select two students from each group by using random numbers. In this case, the random numbers are as follows:

Group 1   Students 5 and 4    Group 2   Students 5 and 2
Group 3   Students 1 and 3    Group 4   Students 3 and 4

The stratified sample then consists of the following people:

\begin{array}{llllll}\text { Peterson, John } & \text { M } & \text { Fr } & \text { Smith, Nancy } & \text { F } & \text { Fr } \\ \text { Meloski, Gary } & \text { M } & \text { Fr } & \text { Carson, Susan } & \text { F } & \text { Fr } \\ \text { Brown, Danny } & \text { M } & \text { So } & \text { Toms, Debbie } & \text { F } & \text { So } \\ \text { Lyons, Larry } & \text { M } & \text { So } & \text { Unger, Roberta } & \text { F } & \text { So }\end{array}