This exercise contains only parts b,c, and d. b) Using the 3-year moving average, provide the forecast from periods 4 through 12 (round your responses to one decimal place). c) Using the 3-year weighted moving average with weights 0.20,0.30, and 0.50 , using 0.50 for the most recent period, provide the forecast from periods 4 through 12 (round your responses to two decimal places). d) Mean absolute deviation for the forecast developed using the 3-year moving average is 2.16 and for the 3-year weighted moving average is 2.44 . Based on this information, the better forecast is achieved using the approach