#### Answer

Cluster sample.

#### Work Step by Step

The author selects 20 different clusters at random that have all the different kind of subjects Then, he samples every single subject in the cluster. Therefore it is a cluster sample.

Published by
Pearson

ISBN 10:
0321836960

ISBN 13:
978-0-32183-696-0

Cluster sample.

You can help us out by revising, improving and updating this answer.

Update this answerAfter you claim an answer you’ll have **24 hours** to send in a draft. An editor
will review the submission and either publish your submission or provide feedback.