#### Answer

a. z

#### Work Step by Step

z test can be used to test the difference between two sample means when the population variances are known

Published by
McGraw-Hill Education

ISBN 10:
0078136334

ISBN 13:
978-0-07813-633-7

a. z

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.