A pollster randomly samples 145 Democrats, 154 Republicans and 19 Independents (all registered voters) in Metro City and asks each poll participant which mayoral candidate he or she prefers.
Identify the kind of sample that the pollster is using.
A) cluster sample
B) voluntary response sample
C) sample of convenience
D) stratified sample

Question

Quizplus · Accepted Answer

The pollster is using a stratified sample, because the population (registered voters in Metro City) has been divided into three strata based on political affiliation (Democrats, Republicans, and Independents), and then a random sample has been taken from each stratum. This ensures that the sample is representative of the entire population, and allows for more precise estimation of the preferences of each political group.

A Pollster Randomly Samples 145 Democrats, 154 Republicans and 19