6. The demand manager of Maverick Jeans is responsible for ensuring sufficient warehouse space for the finished jeans that come from the production plants. It has occasionally been necessary to rent public warehouse space, something that Maverick would like to avoid. In order to estimate the space requirements the demand manager is evaluating moving-average forecasts. The demand (in 1,000 case units) for the last fiscal year is shown below.

Month 1 2 3 4 5 6 7 8 9 10 11 12 Demand 20 18 21 25 24 27 22 30 23 20 29 22

a. Use a three-month moving average to estimate the month-in-advance forecast of demand for months 4–12 and generate a forecast for the first month of next year. Calculate the average forecast error and mean absolute error.