The following table shows the nominal returns on Costaguanan stocks and the rate of inflation. a. What was the standard deviation of the market returns? (Note: Use the method for calculating variance and standard deviation described n Section 7-2 of the text.) (Do not round intermediate calculations. Round your answer to 1 decimal place.) Standard deviation [ ] % b. Calculate the average real return. (Negative value should be indicated by a minus sign. Do not round intermediate calculations. Round your answer to I decimal place.) Average real return [ ] %