Here are the returns on two stocks. Digital Executive Cheese Fruit January +14 +8 February -4 +2 March +6 +5 April +8 +12 May -5 +3 June +4 +6 July -3 -4 August -9 -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?