In general, the z test is more powerful than the t test because _________.
A) with the z test, the sample mean is closer to the population mean than with the t test
B) with the t test we lose a degree of freedom
C) the standard deviation of the sample raw scores is larger with the t test
D) with the z test, we know ó , whereas with the t test, we must estimate it.

Question

Quizplus · Accepted Answer

The z test assumes knowledge of the population standard deviation (ó), whereas the t test must estimate it from the sample data. This makes the z test more powerful than the t test.

In General, the Z Test Is More Powerful Than the T