The standard deviation of the market-index portfolio is 20%. Stock A has a beta of 1.50 and a residual standard deviation of 30%. Required: a. Calculate the total variance for an increase of 0.15 in its beta. (Do not round intermediate calculations.) b. Calculate the total variance for an increase of 3% in its residual standard deviation. (Do not round intermediate calculations.) The following figure shows plots of monthly rates of return and the stock market for two stocks. Required: a. Which stock is riskier to an investor currently holding a diversified portfolio of common stock? Stock A Stock B b. Which stock is riskier to an undiversified investor who puts all of his funds in only one of these stocks? Stock A Stock B A portfollo's expected return is 12%, its standard deviation is 20%, and the risk-free rate is 4% Which of the following would make for the greatest increase in the portiolio's Sharpe ratio? (You may select more than one answer.) Check Af That Apply An increase of 1 in expected retuth. A decrease of thi in the risk.free rate. A decrease of thi in its standard deviation