Method 4: Moving Average, n = 4

This table is history used in the Calculation of MAD, given Periods of Best Fit = 5, n = 4:

Past Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
1	None	None	None	125	122	137	140	None	None	None	None	None

This is the Moving Average forecast for the Holdout Period, Given n = 4:

Calculation	Month
(125 + 122 + 137 + 140) / 4 = 131	August
(122 + 137 + 140 + 129) / 4 = 132	September
(137 + 140 + 129 + 131) / 4 = 134.25 or 134	October
(140 + 129 + 131 + 114) / 4 = 128.5 or 129	November
(129 + 131 + 114 + 119) / 4 = 123.25 or 123	December

This table is the results of the Moving Forecast Average:

Past Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
1	None	None	None	None	None	None	None	131	132	134	129	123

This table is the Actual Sales History for the Holdout Period:

Past Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
1	None	None	None	None	None	None	None	129	131	114	119	137

Sum of Actuals equals (129 + 131 + 114 + 119 + 137) = 630.

Sum of Forecasts equals (131 + 132 + 134 + 129 + 123) = 649.

POA ratio equals (649 / 630) * 100 percent = 103.01 percent.

Based on these two choices, the Moving Average, n = 4 method is recommended because it has POA closest to 100 percent for the given holdout period.