Hello, I would like to check my answers for these problems. Thank you

MATH 137 Project4 Name: Financial data for the rates of return of two stocksA and B for 4 years is as per table. year A B Probability 1 0.4 0.8 0.25 2 0.7 1.2 0.25 3 -0.5 -0.6 0.25 4 0.6 1.0 0.25 A portfolio of the two stocks puts equal amount of money in A and B. Find the covariance ofA and B. Find the expected value of the portfolio rate of return. Find the standard deviation of the portfolio rate of return Find the Sharpe Ratio; that is the ratio of the expected value to the standard deviation. A random sample of 225 exams score drawn from a large population of students has a mean of 60 and a sample standard deviation of9. 3. Estimate the population mean with a confidence level of 95%. 7