Here are the returns on two stocks.

		Digital Cheese			Executive Fruit
January			+18			+7
February			2			+1
March			+4			+4
April			+6			+16
May			3			+2
June			+3			+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?