Here are the returns on two stocks.

	Digital Cheese	Executive Fruit
January	+17	+9
February	2	+1
March	+4	+5
April	+6	+15
May	3	+2
June	+2	+5
July	1	2
August	7	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?