Question

question 10 of 30
dr. elser wanted to do a survey on students and drug use. which of the
following is a random sample?

a. every fifth student on the school roll sheet

b. all of these are correct.

c. two of the honors classes and two of the average classes

d. students who volunteered

Explanation:

• Option A: Selecting every fifth student on the school roll sheet is a form of systematic random sampling. In systematic random sampling, we first order the population (here, the school roll sheet) and then select elements at a fixed interval (every fifth student). This gives each student an equal chance of being selected if the starting point is randomly chosen.
• Option C: Selecting two of the honors classes and two of the average classes is a form of stratified sampling. Stratified sampling divides the population into subgroups (strata) - in this case, honors and average classes - and then samples from each stratum. However, it is not a simple random sample. A simple random sample would not pre - divide the population into such non - random subgroups for sampling.
• Option D: Students who volunteered are a self - selected sample. Self - selected samples are often biased. For example, students who have strong opinions (either for or against drug use) may be more likely to volunteer, and this does not represent the entire student population fairly.

Answer:

A. Every fifth student on the school roll sheet