Sue Sayer is employed as a forecasting analyst for the Barry M. Stiff Casket Corporation. Ms. Sayer has collected the following sales data on Stiff's best-selling casket, Model 12-A: Period Sales 1 25 2 35 3 30 4 37 5 40 6 42 7 38 8 45 9 50 a. What's the four-period moving average forecast for period 7 made at the end of period 6? b. If the forecast for period 1 were 20, what would be the forecast for period 2 made at the end of period 1, using basic exponential smoothing and a smoothing constant of = 0.2 ? c. If the base at the end of period 7 were 39 and the trend at the end of period 7 were 4 (= 0.2, = 0.4), what would be the forecast for period 9 made at the end of period 8? d. Given the model described in c, what would be the forecast for period 11 made at the end of period 9? e. Given the model described in c and d, what would be the forecast for period 12 made at the end of period 9? f. What would be the mean absolute deviation of forecast errors, given that forecasts for periods 6, 7, 8, and 9 were 40, 35, 45, and 65, respectively?