When carrying out a t test for independent means
A)the medians of the two populations are assumed to be equal.
B)the null hypothesis is rejected if the computed t score is more extreme than the cutoff t score.
C)only the .01 significance level should be used because of the greater power compared to a t test for dependent means.
D)only the .10 significance level should be used because of the assumption that the variances of the two distributions should be equal.

Question

Quizplus · Accepted Answer

In a t-test for independent means, the null hypothesis is that the means of the two populations are equal. The computed t score is compared to a cutoff t score (obtained from a table with degrees of freedom calculated based on the sample sizes and assumption of equal variances) to determine whether to reject the null hypothesis or not. Therefore, choice B correctly describes the decision rule for rejecting the null hypothesis in this type of t-test. Choices A, C, and D are incorrect statements about t-tests for independent means.

When Carrying Out a T Test for Independent Means