Suppose Bellevue University accepts new students into its program year-round on a tri-semester schedule (Fall, Spring, and Summer). Forecasting future enrollments helps the school ensure it has the proper resources to accommodate the student body. The following data show the number of students who enrolled each semester for the last four academic years. (Year 4 is the most recent year).

These data can also be found in the Excel file Bellevue.

xlsx.

Enrollment Semester Year 1 Year 2 Year 3 Year 4 Fall 267 278 270 274 Spring 75 69 95 81 Summer 24 37 43 55

a. Construct a graph showing the student enrollment over time.

b. Forecast the student enrollment for each semester in Year 5 using seasonal dummy variables and a best subsets regression.

c. Interpret the meaning of the coefficients for the seasonal dummy variables.

d. Calculate the MAD for this forecast.

AppendixLO1