Exponential smoothing forecast Smoothing constant: 0.8 (iii) Enter appropriate formulae in the shaded cells to calculate an exponential smoothing forecast for week 9 demand. You should use the smoothing constant specified above and week one demand as the starting forecast for week two. (iv) Use the forecasts from weeks 4 to 8 to calculate the MAPE. Week 1 2 3 4 5 6 7 8 Starting forecast 45 Demand (00s) 45 40 38 31 43 31 42 46 Error Forecast for next week MAPE: Absolute percentag e error Exponential smoothing forecast Smoothing constant: 0.8 (iii) Enter appropriate formulae in the shaded cells to calculate an exponential smoothing forecast for week 9 demand. You should use the smoothing constant specified above and week one demand as the starting forecast for week two. (iv) Use the forecasts from weeks 4 to 8 to calculate the MAPE. Week 1 2 3 4 5 6 7 8 Starting forecast 45 Demand (00s) 45 40 38 31 43 31 42 46 Error Forecast for next week MAPE: Absolute percentag e error