What are the approximate and exact expected real returns

Question

Problem

Consider the following information about three stocks:

State of Economy       Probability       Stock A        Stock B       Stock C
Boom                             0.20               0.24            0.36            0.55
Normal                           0.55               0.17            0.13            0.09
Bust                               0.25               0.00           -0.28           -0.45

Task

1. 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?

2. 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?