a. Calculate the expected rate of return, r^B, for Stock B(r^A=15.10%.) Do not round intermediate calculations. Round your answer to two decimal places. % b. Calculate the standard deviation of expected returns, A, for Stock A(B=20.87%.) Do not round intermediate calculations. Round your answer to two decimal places. % Now calculate the coefficient of variation for Stock B. Do not round intermediate calculations. Round your answer to two decimal places