Question

3. We obtain autocorrelation function of residuals of the five autoregressive models: AR(1), AR(2), AR(3), AR(4) and AR(5). Choose a model that performs reasonably well, according to the plots of autocorrelation function. Explain the reason (no more than 20 words.) Autocorrelation function for AR(1) model Series ar1$residuals 1.0 RO 0.6 ACF 0.4 -0.2 0.0 0.2 0 5 10 15 Lag Autocorrelation function for AR(2) model Serles ar2$residuals 1.0 RO 0.6 ACF 0.4 -0.2 0.0 0.2 0 5 10 15 Lag

Answer 1

According to the plot of autocorrelation function(ACF) residual of AR(1) model is perform resonably well, since there is only one

Significant lag( only one line outside the bounds by ignoring 1st line )  i.e order is one for Model of AR