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

Multiple Choice

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.