Question AC/PAC-Function / AR(p) MA(q) ARMA(p,q)

[Julian Hunzinger]

Hi,

I have a question regarding the interpretation and selection of an appropriate process. I examined the differenced version of an exchange rate DEXUSUK in STATA and obtained the following ACF and PACF. I am considering an ARMA (2,2) process since both the ACF and PACF cut off after the second lag, but I'm not entirely sure as I have always followed the following schema:

PACF
Breaks off Decrease
ACF Breaks off ??? MA
Decrease AR ARMA


Can someone help clarify if this is correct or how to proceed in this case?

Hint: I have checked the residuals, they have the same AC and PAC.

Thank you in advance.