Question

To investigate the efficacy of a diet, a random sample of 16 male patients is drawn from a population of adult males using the diet. The weight of each individual in the sample is taken at the start of the diet and at a medical follow-up 4 weeks later. Assuming that the population of differences in weight before versus after the diet follows a normal distribution, the t-test for related samples can be used to determine if there was a significant decrease in the mean weight during this period. Suppose the mean decrease in weights over all 16 subjects in the study is 3.0 pounds with the standard deviation of differences computed as 6.0 pounds.

a) The t test should be _______-tailed. (one or two)

b) The computed t statistic is _______.

c) There are _______ degrees of freedom for this test.

d) The critical value for a one-tailed test of the null hypothesis of no difference at the α = 0.05 level of significance is _______.

e) A one-tailed test of the null hypothesis of no difference would _______ (be rejected/not be rejected) at the α = 0.05 level of significance.

Answer 1