P8-12 Normal probability distribution Answer the following questions, assuming that the rates of return associated with a given asset investment are normally distrib- uted; that the expected return, 7, is 18.9%; and that the coefficient of variation, CV, is 0.75. a. Find the standard deviation of returns, o. b. Calculate the range of expected return outcomes associated with the following probabilities of occurrence: (1) 68%, (2) 95%, (3) 99.7%