A sample of 2,000 was sought to estimate the average achievement in science of fifth graders in a city’s public schools. The average fifth grade enrollment in the city’s elementary schools is 100 students. Thus, 20 schools were randomly selected and within each of those schools all fifth graders were tested. What sampling technique was used?

"Clustering sampling" is the correct answer.

Step-by-step explanation:

If our entire demographic has been separated into segments or groupings, people employ clustering sampling. Those same groupings constitute diverse structurally and therefore are necessarily the same thing uniform.Researchers choose certain of the globular groupings, which are taken throughout the sampling one for each of the specified cluster centers.