Suppose the actual sales and the forecasted or smoothed sale

Suppose the actual sales and the forecasted, or smoothed sales, for the past 5 months have been

Actual      Smoothed   

54.4

76.8            54.4

75.5            72.3

53.2            74.8

39.2       57.6

What is the Mean Absolute Error of the smoothed series? (please round your answer to 1 decimal place)

Solution

The mean absolute error (MAE) value of the smoothed series is computed as the average absolute error value. If this value is 0 (zero), the fit (forecast) is perfect.

MAE = average absolute error value = [76.8-54.4+75.5-72.3+74.8-53.2+57.6-39.2]/4 = 16.4