can someone help me do this without using excel?

3. (30 points) - Rate of returns for A and B companies in different states of nature are provided in the following table: State of nature Probability Rate of return on A's share (% Rate of return on B's share (%) 10 Weak Average Strong Very strong 0.3 0.5 0.1 0.1 a. Find the expected retum on companies Gamma and Theta shares. b. Calculate the standard deviation of retum for both shares. c. If an investor invests 80% in Gamma share and 20% in Theta share, find the expected retum and the standard deviation of return on this portfolio