Expected return and Expected risk premium are correct, I just need help with Variance and Standard Deviation.

Consider the following information on a portfolio of three stocks: State of Probability of Stock A Stock B Economy State of Economy Rate of Return Rate of Return Boom .05 .35 Normal .13 .15 Bust Stock C Rate of Return .12 .52 .36 .57 .23 .19 -14 -38 Required: (a) If your portfolio is invested 42 percent each in A and B and 16 percent in C, what is the portfolio's expected return, the variance, and the standard deviation? (Do not round intermediate calculations. Round your variance answer to 5 decimal places (e.g., 32.16161) and input your other answers as a percentage rounded to 2 decimal places (e.g., 32.16).) Expected return Variance Standard deviation 9.71% 0.03575 19.64% (b) If the expected T-bill rate is 3.9 percent, what is the expected risk premium on the portfolio? (Do not round intermediate calculations. Enter your answer as a percentage rounded to 2 decimal places (e.g., 32.16).) Expected risk premium 5.81%