kimda lost for this one, please help. Also, please provide me the full steps for this one. thx a lot. ;)

State of Economy Boom Good Poor Bust Probability of State of Economy 0.15 0.45 0.35 0.05 Rate of Return if State Occurs Stock A Stock B Stock C 0.30 0.45 0.33 0.12 0.10 0.15 0.01 -0.15 -0.05 -0.06 -0.30 -0.09 a. Your portfolio is invested 30 percent each in A and C, and 40 percent in B. What is the expected return of the portfolio? b. What is the variance of this portfolio? The standard deviation