If 15 research participants take a pretest and a posttest with a mean change score of 1.5, and if the standard deviation of the comparison distribution is .5, what is the t score?
A)1.5/(15 - 1)= .11
B)1.5/15 = .10
C)1.5/.5 = 3.00
D)15/1.5 = 10

Question

Quizplus · Accepted Answer

The formula for calculating the t score is (M1 - M2) / (s / sqrt(n)), where M1 is the mean of the posttest scores, M2 is the mean of the pretest scores, s is the standard deviation of the comparison distribution, and n is the number of participants. In this case, M1 - M2 = 1.5, s = 0.5, and n = 15. Therefore, the t score is (1.5) / (0.5 / sqrt(15)) = 3.00.

If 15 Research Participants Take a Pretest and a Posttest