Data setglobal_economycontains the annual Exports from many countries. Select USA to analyse. When computing the accuracy take the first 45 rows as the training and the rest 12 rows as testing. Choose these alpha and beta combination - (0.7, 0.6)

1. Plot the Exports series and discuss the main features of the data.
2. Use an ETS(A,N,N) model to forecast the series, and plot the forecasts.
3. Compute the RMSE values for the training data.
4. Compare the results to those from an ETS(A,A,N) model. (Remember that the trended model is using one more parameter than the simpler model.) Discuss the merits of the two forecasting methods for this data set.
5. Compare the forecasts for the test data for both methods. Which do you think is best?