Question

A researcher would like to study the average amount of debt owed by retired people in the United States. What could be an example of a strata sampled? Select all that would apply.

retirees from different states in the United States
retirees who had different jobs in the United States
retirees with different education levels
retirees who lived near the researcher
retirees who returned a survey sent in the mail

Answer 1

Retirees who had different jobs and different income levels.

In stratified sampling, the population is broken up into groups ("strata") that are distinctly different from each other.