The table below shows the one-year sales data for a certain part. Month January February March April May June Demand 133 191 179 117 107 178 Month July August September October November December Demand 186 120 190 139 115 167 a. Compute the one-step-ahead 3-month and 6-month moving average forecasts for July through December. b. Compute the MAD for the forecasts obtained in part (a). What effect does increasing N from 3 to 6 have on the forecasts? c. Use the arithmetic average of the first six months of data as a baseline to initialize the exponential smoothing. Compute the one-step-ahead exponential smoothing forecasts for July through December, assuming a = 0.25. d. Compare the accuracy of the forecasts obtained in part (c) with the one-step ahead six-month moving-average forecasts obtained in part (a)