The following are estimates for two stocks. The market index has a standard deviation of 18% and the risk-free rate is 6%. a. What are the standard deviations of stocks A and B ? (Do not round intermediate calculations. Round your answers to 2 decimal places.) Answer is complete but not entirely correct. b. Suppose that we were to construct a portfolio with proportions: Compute the expected return, standard deviation, beta, and nonsystematic standard deviation of the portfolio. (Do not round intermediate calculations. Enter your answer for Beta as a number, not a percent. Round your answers to 2 decimal places.)