QUESTION 7 For this exercise use dataset visitors, the monthly Australian short-term overseas visitors data, May 1985April 2005 A. Split your data into a training set and a test set (comprising the last two years of available data). a. Forecast the two-year test set using Holt-Winters' multiplicative method b. Forecast the two-year test set using seasonal naive method 8. Which method gives the best forecasts and why?