Here are the returns on two stocks.

	Digital Cheese	Executive Fruit
January	+15	+8
February	4	+2
March	+6	+7
April	+8	+15
May	5	+3
June	+4	+8
July	3	4
August	9	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 stocks.

c. Is the variance more or less than halfway between the variance of the two individual stocks?