Mean absolute percentage error

The mean absolute percentage error (MAPE), also known as mean absolute percentage deviation (MAPD), is a measure of prediction accuracy of a forecasting method in statistics. It usually expresses the accuracy as a ratio defined by the formula: MAPE = 100 1 n ∑ t = 1 n | A t − F t A t | {\displaystyle {\mbox{MAPE}}=100{\frac {1}{n}}\sum _{t=1}^{n}\left|{\frac {A_{t}-F_{t}}{A_{t}}}\right|} Where At is the actual value and Ft is the forecast value.

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