Suppose we have a time series data of a book store's sales. We build a linear exponential smoothing model (LES) with Alpha = 0.5, Beta = 0.2. Please ll in all the blanks. Please round your results into 2 decimal places. Period Sales Level Trend Forecast Error 1 17.00 2 19.00 3 20.00 4 22.00 20 00 1.50 21.50 2 - 5 3.00 21 75 23 30 0 30 6 26.00 1.33 7 27.00 25.34 1 65 26.99 0.01 8 26.00 26.99 1 65 28.65 2 65 9 28.00 27.32 1 39 28 71 0.71 10 29.00 28.36 1.32 29.67 0.67