Problem 2 [25 pts] Harlen Industries has a simple forecasting model for monthly demand. The following table shows the forecast and actual demand in the first eight months last year. Month 1 2 3 4 5 6 7 8 Forecast 140 140 140 140 140 150 150 150 Actual 137 133 150 160 180 170 185 205 a. Compute the MAD for each month b. Compute the tracking signal for each month (you can calculate using excel and show the result). c. Based on your answers to (a) and (b), comment (in one or two sentences) on Harlen's method of forecasting. d. Comparing forecasts and actual demands, what do you think is missing in the current forecasting model