The number of patients in a clinic in the past 7 months are:
647, 723, 750, 625, 536, 362, 772
What is the value of MAPE (in percent) if we use a four-month moving average method?
Use at least 4 decimal places.
Solution:
Let assume, 647 is the number of patients for Month 1 and 772 is the number of patients for Month 7.
As per Four Month Moving Average -
Forecast = Average of Past four period Actual Number of Patients
Forecast for Month 5 = (647 + 723 + 750 + 625) / 4 = 686.25
Forecast for Month 6 = (723 + 750 + 625 + 536) / 4 = 658.50
Forecast for Month 7 = (750 + 625 + 536 + 362) / 4 = 575
Absolute Error = |Actual - Forecast|
Absolute Error for Month 5 = | 536 - 686.25 | = 150.25
Absolute Error for Month 6 = | 362 - 658.50 | = 296.50
Absolute Error for Month 7 = | 772 - 575 | = 197
Absolute % Error = Absolute Error*100/Actual Value
Absolute % Error for Month 5 = 150.25 * 100 / 536 = 28.03172 %
Absolute % Error for Month 6 = 296.50 * 100 / 362 = 81.9061 %
Absolute % Error for Month 7 = 197 * 100 / 772 = 25.518135 %
MAPE = Average of Absolute % Error
MAPE = ( 28.03172 + 81.9061 + 25.518135) / 3
MAPE = 45.151985 %