Here are the returns on two stocks Digital Executive Cheese +13 Fruit January February March ril +15 May June July August a-1. Calculate the variance and standard deviation of each stock. (Do not round intermediate calculations. Round your answers to 2 decimal places.) Executive Fruit Digital Cheese Retum Return Variance Standard deviation a-2. Which stock is the riskier if held on its own? Digital Cheese Executive Fruit 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.) Portfolio Month Return January February March April May June July August