---
title: "Auto-regressive moving average model of order (2,2)"
output: html_document
---

## AirPassengers data

- Make a decomposition of the `AirPassengers` data and comment on the correlogram of the random component (try both an additive and multiplicative decomposition).

- Fit an ARMA(p,q) model for values of $p$ and $q$ no greater than 2 to the random component.
Choose the best fitting model based on the AIC and comment on the correlogram of this model's residuals.