A sociologist wants to learn about Utahns opinions about the
A sociologist wants to learn about Utahns’ opinions about the Public Affairs Act. In order to make sure he is measuring the opinions of all groups, he determines what portion of the population is urban, rural, and suburban, and takes a sample of each, of sizes proportional that the demographic breakdown of the whole population.
What kind of study design is this?
A. Simple random sample
 B. Stratified random sample
 C. Voluntary response sample
 D. Matched pairs experiment
 E. Double-blind experiment
 F. Controlled experiment
Solution
B. Stratified random sample is the answer.
(Since the population is first classified into stratas as rural, urban and semi urban and then random samples are taken)

