ans all of them please

Here are the returns on two stocks. Digital Cheese +13 Executive Fruit +6 +5 +4 January February March April May June July August + + + + + NU NAD +2 -4 +3 -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 stock c. Is the variance more or less than halfway between the variance of the two individual stocks