The military contractor mentioned earlier decided to do a 3 month weighted moving average. The weights are 60% for the most recent, 30 percent for the middle period and 10% for the oldest data. This uses three months of data. The forecast and accuracy data are in the following file. Weighted moving average 60 - 30 - 10 Three month moving average: Month 1=0.6 Month 2=0.3 Month 3=0.1. Period 1 =1200, Period 2=985, Period 3=1010, Period 4=910, Period 5=1155, Period 6=1052, Period 7=1150, Period 8=1048, Period 9=956 and Period 10=980