A researcher comparing the means of two groups calculates the t-test for independent means and reports the following result: t(28) = 2.11, p

Question

A researcher comparing the means of two groups calculates the t-test for independent means and reports the following result: t(28) = 2.11, p <.05. This research study consisted of a TOTAL of ______ participants.
A) 14
B) 15
C) 28
D) 30

Quizplus · Accepted Answer

The degrees of freedom for the t-test are calculated as the sum of the sample sizes minus 2 (df = n1 + n2 - 2). In this case, we only have information about one sample size (n1), which is equal to 28 (based on the reported degrees of freedom). Therefore, the total sample size would be equal to n1 + n2 = 28 + n2. We cannot determine n2 with the information given. However, we do know that the total sample size must be greater than 28, so the closest option is D with 30 participants.

A Researcher Comparing the Means of Two Groups Calculates the T-Test