If y1, y2,…, yn are n observed values and ŷ1, ŷ2,…, ŷn are the corresponding values predicted (perhaps by some model), then the MAE is There are several similar statistics, all of which provide information about the extent of the agreement between the observed and predicted values. The mean absolute percentage error (MAPE) isthe mean squared error (MSE) is given by and the root mean squared error (RMSE) is .