Here are the returns on two stocks. Digital Cheese Executive Fruit January 415 +8 1-2 +1 February March April) +4 46 +16. May -3 +2 June +2 July -2 August -1 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? Complete this question by entering your answers in the tabs below. Reg A1 Req A2 Req B Req C 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.) Portfolio Month Return January February March April May June 11.50