Task 3 - Demand Forecasting Data is given for the sales of a leading mobile company across Oman. The sales of the mobile company over the past 12-month period for the year 2021 is given in Table T3. Table T3 - Sales Data of Year 2021 a. Calculate the monthly demand forecast for the 6-month period from January 2022 to June 2022 using 4-month weighted moving average method. Use weights of 0.4,0.3,0.2 and 0.1, with heavier weights for more recent months. (10 Marks) b. Develop a simple regression model of forecast with the data given in the Table T3 and determine the mean squared error (MSE) of the model. (10 Marks) c. Use exponential smoothing with smoothing parameter =0.6 and =0.3 to compute the demand forecast for January 2022 to December 2022. Use linear average for the first three months to forecast the demand of January 2022. Determine the Mean Absolute Deviation (MAD) of the forecast