Figure 4. The ACF graph and PACF graph of the residuals for the ARIMA (2,1,0) × (0,1,1)₁₂ model.

ACF=autocorrelation function, PACF=partial autocorrelation fuction. As their correlation values are not outside the confidence intervals (CI) limits, the residuals error is considered to be white noise indicating that this model is appropriate for prediction.