Here are the returns on two stocks. January February March April May June July August Digital Cheese +18 -4 +6 +8 -5 +4 -3 -9 Executive Fruit +8 +1 +5 +16 +2 +6 -4 -3 a-1. Calculate the variance and standard deviation of each stock. (Do not round intermediate calculations. Round your answers to 2 decimal places.) Variance Standard deviation Digital Cheese Retum 67.86% 8.24 Executive Fruit Return 36.36% 6.03 a-2. Which stock is the riskier if held on its own? Digital Cheese O Executive Fruit O b. Now calculate the returns in each month of a portfolio that invests an equal amount each month in the two stocks. (Negative amounts should be indicated by a minus sign. Do not round intermediate calculations. Round your answers to 2 decimal places.) Month Portfolio Return January February March April May June July August