Chapter 12, Problem 2E

(a)

To determine

To explain do you think the group was using a simple random sample.

Answer to Problem 2E

No, they are not using.

Explanation of Solution

It is given in the question that for their class project a group of statistics students decided to survey the student body to access opinions about the proposed new student centre. Thus, as we see the sample design in the question, we can say that is very unlikely that they are using an SRS because it would be very unlikely to get a sample with exactly $50$ students from each grade.

(b)

To determine

To find out what kind of design do you think they are using.

Answer to Problem 2E

They are using stratified sample design.

Explanation of Solution

It is given in the question that for their class project a group of statistics students decided to survey the student body to access opinions about the proposed new student centre. Thus, by looking at the design of the design they conducted to do the survey we can say that they are using stratified sample design because there are dealing with the four strata that are first year, sophomore, junior and senior.