please show work. Nothing is missing. Any formula can be used. all data here

Your manager is trying to determine what forecasting method to use.
Based upon the following historical data, calculate the following forecast and specify what procedure you would utilize.
	Month	Actual Demand
	1	62
	2	65
	3	67
	4	68
	5	70
	6	75
	7	74
	8	76
	9	77
	10	79
	11	83
	12	81
a) Calculate the simple three-month moving average forecast for periods 4-12.
b) Calculate the weighted three-month moving average using weights of 0.5, 0.3, and 0.2 for periods 4-12.
c) Calculate the mean absolute deviation (MAD) for the forecasts made by each technique in periods 4-12.
Which forecasting method would be preferable?