(a) A time series model is simulated with 1000 samples. The figures follow show the sample ACF and sample PACF.

-0.2 0.2 0.6 1.0 ACF Partial ACF -0.1 -0.3 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Lag Lag Figure 2.1: Sample ACF and sample PACE