Angelika wants to study how sixth graders perform in math exams. She obtains a list of all districts in the state, randomly selects 5% of the districts, and administers achievement tests to all sixth graders in these districts. This sampling method used by Angelika is called _____ sampling.

A) stratified random
B) quota
C) cluster
D) haphazard

Cluster Sampling

A sampling technique where the researcher divides the population into separate groups, or "clusters," and a sample of these clusters is then selected for study.

Stratified Random

This refers to a sampling method where the population is divided into subgroups (strata) that share similar characteristics, and a random sample is then drawn from each stratum.

Achievement Tests

Standardized tests designed to assess how much knowledge and skills a person has acquired in a specified area.