please help me figure out the last two and why they are wrong

Rate of Return If State Occurs Stock A Stock B Stock C State of Economy Boom Normal Bust Probability of State of Economy .25 .50 .25 .35 .17 .40 .15 -32 .52 .13 -40 .01 a-1. If your portfolio is invested 35 percent each in A and B and 30 percent in C, what is the portfolio expected return? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) a-2. What is the variance? (Do not round intermediate calculations and round your answer to 5 decimal places, e.g., 16161.) a-3. What is the standard deviation? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) b. If the expected T-bill rate is 3.70 percent, what is the expected risk premium on the portfolio? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) C-1. If the expected inflation rate is 3.30 percent, what are the approximate and exact expected real returns on the portfolio? (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) C-2. What are the approximate and exact expected real risk premiums on the portfolio? (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) X Answer is complete but not entirely correct. Portfolio expected return 12.30 % Variance 0.05311 a- 1. a- 2. a- 3. b. C- 1. Standard deviation 23.05 % Expected risk premium 8.60% Approximate expected real return 9.00 % 8.71 % Exact expected real return Approximate expected real risk premium C- 2. uni 5.30 X % Exact expected real risk premium 5.13 X %