Look at the time-series data listed on the Excel document titled "Demand for Product Alpha". You want to generate forecast for the monthly demand of product Alpha using the exponential smoothing method with: [A] a smoothing constant of 0.15. [B] a smoothing constant of 0.23. [C] a smoothing constant of 0.31. [D] a smoothing constant of 0.43. Assume the forecast for period month 1 is 104 units. You must use at least 4 decimal places in your calculation and answer. Answer the following questions: The value of MAD is The value of MAPE is The value of RMSE is units. percent. units. The actual demands for product Alpha in the past 15 months are shown below. Month Actual Demand (u) 1 75 2 70 3 139 4 132 5 83 6 88 7 129 8 118 9 132 10 115 11 77 12 92 13 128 14 136 15 127