Use the following Sales Data to

a) Develop a 4-month moving average forecast, a forecast for January, and compute the MAD.

b)Develop 3-month moving average forecast, a forecast for January, and calculate a MAD.

c) Which model should be used in the future? Explain why this is your answer.

	Month	Actual Shed Sales
1	January	10
2	February	12
3	March	13
4	April	16
5	May	19
6	June	23
7	July	26
8	August	30
9	September	28
10	October	18
11	November	16
12	December	14
13	January