A researcher is comparing two groups.The population mean from which the samples come is known, but not the population standard deviation.Which test should be used?
A) either the t or z test
B) neither the t or z test because more information is needed
C) z test because the population parameters are known
D) t test because standard deviation for the population must be estimated

Question

Quizplus · Accepted Answer

As the population standard deviation is not known, the t-test should be used which estimates the standard deviation from the sample data. Additionally, as the researcher is comparing two groups, a two-sample t-test would be appropriate to use. The z-test assumes that the population standard deviation is known, so it cannot be used in this scenario.

A Researcher Is Comparing Two Groups