Car sales at a dealership are shown quarterly as follows: Period Year Quarter Sales 1 1 98 2 1 II 106 3 1 109 4 1 IV 133 5 2 130 6 2 II 116 7 2 III 133 8 2 IV 116 3 138 10 3 II 130 11 3 147 12 3 141 13 144 14 142 15 4 III 165 16 IV 173 - EE-EE-EE-EE 9 1) 150 Points| Estimate sales in period 17 using four-period moving average, simple exponential smoothing with a=0.1, and linear trend equation methods. Evaluate the MAD, MSE and MAPE for forecasted data in each case. Which methods do you prefer? Why? 2) 130 Points) Estimate sales in period 17 using the trend-adjusted exponential smoothing model with a=0.1 and 3-0.15. Evaluate the MAD, MSE and MAPE for forecasted data. Estimate the optimal combination of smoothing constants. Using the optimal smoothing constants, comment whether this method is resulted better forecasts than the ones in Q-1. 3) (20 Points] Using the multiplicative seasonal method, calculate the seasonal indexes and forecast sales in periods 17-20 if the expected sales in year 5 is 660. Car sales at a dealership are shown quarterly as follows: Period Year Quarter Sales 1 1 98 2 1 II 106 3 1 109 4 1 IV 133 5 2 130 6 2 II 116 7 2 III 133 8 2 IV 116 3 138 10 3 II 130 11 3 147 12 3 141 13 144 14 142 15 4 III 165 16 IV 173 - EE-EE-EE-EE 9 1) 150 Points| Estimate sales in period 17 using four-period moving average, simple exponential smoothing with a=0.1, and linear trend equation methods. Evaluate the MAD, MSE and MAPE for forecasted data in each case. Which methods do you prefer? Why? 2) 130 Points) Estimate sales in period 17 using the trend-adjusted exponential smoothing model with a=0.1 and 3-0.15. Evaluate the MAD, MSE and MAPE for forecasted data. Estimate the optimal combination of smoothing constants. Using the optimal smoothing constants, comment whether this method is resulted better forecasts than the ones in Q-1. 3) (20 Points] Using the multiplicative seasonal method, calculate the seasonal indexes and forecast sales in periods 17-20 if the expected sales in year 5 is 660