The following are estimates for two stocks Expected Return Firm-Specific Standard Deviation Stock 12% 20 Beta 0.65 1.15 26% 36 The market index has a standard deviation of 20% and the risk-free rate is 7%. a. What are the standard deviations of stocks A and B? (Do not round intermediate calculations. Round your answers to 2 decimal places.) Stock A Stock B b. Suppose that we were to construct a portfolio with proportions: Stock A Stock B T-bills 0.40 0.40 0.20