7. QI (15 pts): a) Calculate four forecasts using the following data (table 1); First, for periods 4 through 7, develop the exponentially smoothed forecasts using a forecast for period 3 (F3) of 120.0 and an alpha of 0,3 Second, calculate the three-period moving average forecast for periods 4 through Third, calculate the weighted moving average for periods 4 through 7, using weights of 60,30, and .10. Fourth, calculate the combination forecast of above methods for periods 4 through 7. b) Calculate the mean absolute deviation (MAD), and the cumulative sum of forecast error (CFE) for each forecasting procedure (in (a)). Which forecasting procedure would you select? Explain why? Based on the given demand below (without calculations), do you think it would be better if we use a trend-adjusted forecasting method? why? Month Demand 1 120 2. 115 3 125 Table 1 4 119 5 127 6 114 7 120