An insurance company that provides health coverage to employ

An insurance company that provides health coverage to employers is concerned that people are taking too many prescriptions, so it decides to collect a sample of covered employees. The insurer divides the country into geographical regions and randomly selects 30 insureds from each region. What kind of sample is this?

A systematic sample.

A simple random sample.

A stratified sample.

A cluster sample.

Solution

Answer is

A stratified sample.

Because under stratified sampling only, population is divided into strata or groups. As the insurer divides into geographical locatins, this is stratified sample.