Consider austa , the total international visitors to Australia (in millions) for the period XXXXXXXXXX. a. Use auto.arima() to nd an appropriate ARIMA model. What model was selected. Check that the...

Consider austa , the total international visitors to Australia (in millions) for the period 1980-2015.

a. Use auto.arima() to nd an appropriate ARIMA model. What model was selected. Check that the residuals look like white noise. Plot forecasts for the next 10 periods.

b. Plot forecasts from an ARIMA(0,1,1) model with no drift and compare these to part a. Remove the MA term and plot again.

c. Plot forecasts from an ARIMA(2,1,3) model with drift. Remove the constant and see what happens.

d. Plot forecasts from an ARIMA(0,0,1) model with a constant. Remove the MA term and plot again.

e. Plot forecasts from an ARIMA(0,2,1) model with no constant.