show the steps

Consider the following information about three stocks: Instructions: a) If your portfolio is invested 40% each in A and B and 20% in C, what is the portfolio expected return? The variance? The standard deviation? b) If the expected T-bill rate is 3.80%, the expected inflation rate is 3.50% what are the approximate and exact expected real returns on the portfolio? what is the approximate real risk premium? Show your steps