If the z statistic is incorrectly used in lieu of the t statistic when comparing two population means based on independent,small random samples from two normally distributed populations with unknown variances,then the probability of rejecting the null hypothesis __________.
A)increases.
B)decreases
C)remains the same.
D)is 1.
E)is 0.

Question

Quizplus · Accepted Answer

The z statistic assumes that the population variance is known, while the t statistic accounts for the uncertainty in the sample variance. Using the z statistic instead of the t statistic inflates the test's significance level and increases the probability of rejecting the null hypothesis. Therefore, the correct answer is A, which states that the probability of rejecting the null hypothesis increases.

If the Z Statistic Is Incorrectly Used in Lieu of the T