4. Your manager is trying to determine what forecasting method to use. Based upon the following historical data, calculate the following forecast and specify what procedure you would utilize. Month Actual Demand Month Actual Demand 1 62 7 76 2 65 8 78 3 67 9 78 4 68 10 80 5 71 11 84 6 73 12 85 a. Calculate the simple three-month moving average forecast for periods 4 to 12. b. Calculate the weighted three-month moving average using weights of 0.5, 0.3, and 0.2 for periods 4 to 12. c. Calculate the simple exponential smoothing forecast for periods 2 to 12 using an initial forecast (F1) of 61 and an a of 0.3. d. Calculate the mean absolute deviation (MAD) for the forecasts made by each technique in periods 4 to 12. Which forecasting method do you prefer? Why