Question

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. In one study of 110 female first‐year college students (Psychology of Women Quarterly, vol 17, pp.119‐126, 1993), the mean weight was 130.6 pounds at the beginning of the study and 131.4 pounds six months later. The standard deviation was about 20 pounds at each time.

Required:
a. Estimate the change in the mean weight over this six‐month period.
b. Is this sufficient information to find a confidence interval or conduct at estimate about the change in the mean over six months? If not what else do you need to know?

Answer 1

A) - 0.8 Ibs

B) There isn't enough information

The standard deviations of the difference scores is needed

Explanation:

N = 110 female first year college students

Mean weight at beginning of study = 130.6 Ib

Mean weight after six ( 6 ) months = 131.4 Ib

standard deviation = 20 pounds

A) Determine the change in the mean weight over the six(6) months period

mean weight at beginning - mean weight after six(6) months

= 130.6 - 131.4

= -0.8 Ibs

B) Determine if there is sufficient information to find a confidence interval

There isn't sufficient information to determine the confidence interval but in other to determine the confidence interval or conduct an estimate You need standard deviations of the difference scores to calculate the standard error of mean