Hi, In the attachement you can find the output of an ARIMA model with 4 parameters (no intercept): AR1, AR7, MA1 & MA7. I calculated the Yt-1, Yt-7, et-1 & et-7 by myself & multiplied with the parameter estimates: This is my equation: Yt = 0.91689*Yt-1 + 0.99625*Yt-7 - 0.734927Et-1 - 0.78277Et-7 The issue is now that my outcome is not the same as the outcome sas provides. For the first 10 observations however I have the same result, both afterwards I have a big difference. Can anyone help me understanding the difference? Kind regards, Olivier
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