We are interested in the impact of an exercise program on weight. Below is the Excel output from a study to see whether there is evidence of a difference in the mean weight between those in the program vs. those who are not. We want to know if the two are different from each other.

a) State the null and alternative hypotheses for testing if there is evidence of a difference in the two treatments.

b) What is the value of the test statistic for testing if there is evidence of a difference in the two treatments? Explain how you obtain your answer.

c) What is the t-score for testing if there is evidence of a difference in the two treatments? Explain how you obtain your answer.

d) Interpret your results. Is the difference statistically significant? Is it practically significant?

Mean Std Dev n S.E. Exercise Group 145 21 144 1.75 No Exercise 141 14 81 1.56