5. You are forming a portfolio consisting of stocks and bonds. Your portfolio will be 60% stocks and 40% bonds. Stock excess returns have a mean of 6% and a standard deviation of 18%. Bond excess returns have a mean of 2% and a standard deviation of 7%. The correlation between stock and bond excess returns is 0.2. What are the mean and standard deviation of portfolio excess returns? Calculate the Sharpe ratios for stocks, bonds, and the portfolio