Statistics questions

Question 1

The freshman 15 refers to the urban legend that students gain an average of 15 pounds during their freshman year of college. The weights of 100 freshmen at a certain University were observed in August and then re-examined in May. The claim that the mean difference is equal to 15 pounds is tested at a 0.05 significance level. The result is “fail to reject the null hypothesis”.

• What do the results suggest?
• What factors could have affected the results?
• How can these results be used to make changes on campus?

Question 2

In a test of a weight loss program, weights of 40 subjects are recorded before and after the program. Assume that the before/after weights result in r = 0.876.

Is there sufficient evidence to support a claim of a linear correlation between before/after weights?

Does the value of r indicate that the program is effective in reducing weight? Why or why not?