A nutritionist studying weight gain for college freshmen obtains a sample of n = 20 first year student at the state college. Each student is weighed on the first day of school an again on the last day of the semester. The following scores measure the change in weight, in pounds, for each student. A positive score indicates a weight gain during the semester.

+5, +6, +3, +1,+8, +5, +4,+4, +3, -1

+2, +7, +1, +5, +8, 0, +4, +6, +5, +3

a) Sketch a histogram showing the distribution of weight-change scores.

b) Calculate the mean weight change score for this sample

c) Does there appear to be a consistent trend in weight change during the semester?