14 Jeannette Phan is a college student who has just completed her junior year. The following table summarizes her grade point average (GPA) for each of the past nine semesters:

BAGS BAGS YEAR (thousands) YEAR (thousands)

1 4 7 7 2 8 8 9 3 6 9 13 4 6 10 14 5 9 11 16 6 8 YEAR SEMESTER GPA Freshman Fall 2.4 Winter 2.9 Spring 3.1 Sophomore Fall 3.2 Winter 3.0 Spring 2.9 Junior Fall 2.8 Winter 3.6 Spring 3.2

(a) Forecast Jeannette’s GPA for the fall semester of her senior year by using a three-period moving average.

(b) Forecast Jeannette’s GPA for the fall semester of her senior year by using exponential smoothing with a = 0.3.

(c) Which of the two methods provides a more accurate forecast? Justify your answer.

(d) If you decide to use a three-period weighted moving average, find the optimal weights that would minimize MAPE. Is this method an improvement over the previous two methods?