Here are the actual tabulated demands for an item for a nine-month period (January through September). Your supervisor wants to test two forecasting methods to see which method was better over this period.

MONTH ACTUAL MONTH ACTUAL January 110 June 180 February 130 July 140 March 150 August 130 April 170 September 140 May 160

a. Forecast April through September using a three-month moving average.

b. Use simple exponential smoothing with an alpha of .3 to estimate April through September.

Start the forecast with the average of January, March, and April demand.

c. Use MAD to decide which method produced the better forecast over the six-month period.