Which of the following statements is true? If the returns from a security ate normally distributed. 86% of the observations fall within one standard deviation of the expected value Risk - averse investors prefer securities with high standard deviations Standard deviations can be computed for stock returns, but not for bond yields An increase in risk will result in an increase in the standard deviation Calculus of variations (CV) adjusts standard deviations to compare die risk of securities with different expected returns