please answer part (b) and (c), without using excel. thanks!

4. Here are the returns on two stocks Apple January 15 February -3 March 5 April 7 May -4 June 3 July -2 August -8 Meta 7 1 4 13 -3 -2 a. Calculate the variance and standard deviation of each stock. 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. January February March April May June July August Apple 15 -3 5 7 -4 3 -2 -8 Meta 7 1 4 13 2 5 -3 -2 50/50 Portfolio 11 -1 4.5 10 -1 4 -2.5 -5 c. Is the variance more or less than halfway between the variance of the two individual stocks