The standard deviation of the market-index portfolio is 50%. Stock A has a beta of 1.30 and a residual standard deviation of 60%. a. Calculate the total variance for an increase of 0.20 in its beta. (Do not round intermediate calculations. Round your answer to 4 decimal places.) Total variance b. Calculate the total variance for an increase of 10.71% in its residual standard deviation. (Do not round intermediate calculations. Round your answer to 4 decimal places.) Total variance