Read Section 10.3, “Non-stationary seasonal ARIMA models,” on pages 233-234.

Read Section 10.4, “Model specification, fitting, and checking,” on pages 234-241. These are illustrations; they help you with your student project, but they no material to know for the final exam.

Read Section 10.5, “Forecasting seasonal ARIMA models,” on pages 241-245. These are examples; you need not memorize the equations. Any exam problems are structured to be answered intuitively, not by equation.

Many time series are seasonal. Check if the time series in your student project is seasonal. This module help you understand how seasonality affects the observed time series values.