Here are the returns on two stocks.

		Digital Cheese			Executive Fruit
January			+15			+7
February			3			+1
March			+5			+4
April			+7			+13
May			4			+2
June			+3			+5
July			2			3
August			8			2

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?