Question

Dean Halverson recently read that full-time college students study 20 hours each week. She decides to do a study at her university to see if there is evidence that students study an average of less than 20 hours each week. A random sample of 34 students were asked to keep a diary of their activities over a period of several weeks. It was found that he average number of hours that the 34 students studied each week was 17.9 hours. The sample standard deviation of 4.6 hours.

Find the p-value.

Answer 1

Null and Alternative Hypotheses

The following null and alternative hypotheses need to be tested:

Ho: μ = 20

Ha: μ < 20

Test Statistics

The t-statistic is computed as follows:

P-value

df=n−1 = 34 - 1 = 33

Prob(t < -2.662) = 0.005954 (using software) (Ms excel)

=tdist(x,deg_freedom,tails) (tails = 1 one tail and tails = 2 two ail)

=TDIST(2.662,33,1)

+-X-HO_17.9 - 20 s/n 4.6/34

T-Test Results: t-stats = -2.662, p-value =0.006 40 .35 3.0 -25 -20 -15 -10 -0.5 0.0 0.5 10 15 20 25 30 35 40