21. Two different forecasting techniques (F1 and F2) were used to forecast demand for cases of bottled water. Actual demand and the two sets of forecasts are as follows: Chapter Three Forecasting 3 4 74 PREDICTED DEMAND Period Demand F1 F2 1 68 66 66 2 75 68 68 70 72 70 71 72 5 69 72 74 72 70 76 7 80 71 78 78 74 80 a. Compute MAD for each set of forecasts. Given your results, which forecast appears to be more accurate? Explain. 6 8