Consider three stock market indexes: the Dow Jones Industrial Average, the S&P 500, and the Nikkei 225. Suppose you forecast that all three indices will have expected returns of 15% and annual standard deviations of 30%. You forecast that the DJIA and S&P 500 have 0.95 correlation, the DJIA and Nikkei 225 have 0.75 correlation, and the S&P 500 and Nikkei 225 have 0.75 correlation. Could you improve your risk-adjusted returns by diversifying internationally? Why or why not?