QUESTION 4 The owner and manager of LaLa Department Store, has decided to use statistical forecasting to get a better handle on the demand for his major products. One category is major household appliances, such as washing machines, which have a relatively stable sales level. Monthly sales of washing machines last year are shown below. a. [2 Mark] Use the moving average method with n = 3 retrospectively to determine what the forecasts would have been for the last 9 months of last year and error using MAD method. b. [2 Mark] Use the Simple Exponential Smoothing to determine what the forecasts would have been for the last year. (Let the initial estimate of level = 25 and smoothing constant a=0.1) and error using MAD method. C. [1 Mark] Draw the graph plotting the actual sales, Moving Average and the Simple Exponential Smoothing results in one plot. Sales 23 24 Month January February March April May June Month July August September October November December Sales 20 26 21 29 23 28 28 27