Here are the returns on two stocks. January February March April May June July August Digital Cheese +16 -4 +6 +8 -5 +4 -3 -9 Executive Fruit +9 +1 +7 +16 +2 +7 -4 -3 Required: a-1. Calculate the variance and standard deviation of each stock. a-2. Which stock is riskier if held on its own? b. Now calculate the returns in each month of a portfolio that invests an equal amount each month in the two stocks. c. Is the variance more or less than halfway between the variance of the two individual stocks