Please solve this on Excel

5) The correlations between the returns of three stocks, A, B, and C are given in the following table: Stock A B C A 1.00 0.80 0.10 B 1.00 0.15 1.00 The expected rates of return and standard deviations of the stock are as follows: Expected Standard Stock returns deviation A 16% 25% B 12% 22% 15% 25% a) What is the standard deviation of a portfolio invested 25% in stock A, 25% in stock B, and 50% in stock C? b) You plan to invest 50% of your money in the portfolio constructed in part a of this question and 50% in a risk-free asset. The risk-free interest rate is 5%. What is the expected return on this investment? What is the standard deviation of the return on this investment