The freshman 15 is the name of a common belief that college students, particularly women, gain an average of 15 pounds during their first year of college. A recent study ( Journal of American Health , vol. 58, 2009, pp. 223–231) found that female students weighed an average of 133.0 pounds at the start of the school year and an average of 135.1 pounds at the end of the school year. The standard deviation of weights was about 30 pounds at each time. Other reports have been consistent with this finding.
a. Estimate the change in the mean weight
b. Is this sufficient information to find a confidence interval or conduct a test about the change in the mean? If not, what else do you need to know?