The following table gives sales of a certain product during the first four days of a given week. Sales(y,) 32 Day(1) 1 2 3 4 33 28 31 Assume that the simple exponential smoothing, with smoothing constant a = 0.2 and initial smoothing level loy, is appropriate. = (1.1) Compute the estimates of the smoothed levels. (1.2) Compute the estimates of the forecasts made last period. (1.3) Compute the forecast errors. (1.4) Compute the mean absolute deviation. (1.5) Compute the mean square error. (1.6) Compute the mean absolute percentage error. (8) (3) (4) (4) (3) (6) [28]