I am trying to find the arima model that has uncorrelated residuals. I plotted the AC and PAC. I observe that in any of the cases (PAC, AC) there is a decaying signal. Rather, I observe that both series have significant signals at lag 12, 24, 36 and so on. What ARIMA process could I use?
The PAC and AC are displayed in the attached file.
Model.pdf
The PAC and AC are displayed in the attached file.
Model.pdf
