The freshman 15 refers to the urban legend that is the common belief that students gain an average of 15 lb during freshman year. The weights of 100 freshmen at a certain university were observed in August and then in May. The claim that the mean difference is equal to 15 lb 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?