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?