Here are the percentage returns on two stocks. a-1. Calculate the monthly variance and standard deviation of each stock. (Do not round intermediate calculations. Round your answers to 1 decimal places.) a-2. Which stock is the riskier if held on its own? b. Now calculate the variance and standard deviation of the returns on a portfolio that invests an equal amount each month in the two stocks. (Do not round intermediate calculations. Round your answers to 1 decimal places.) c. Is the variance more or less than half way between the variance of the two individual stocks? Complete this question by entering your answers in the tabs below. Calculate the monthly variance and standard deviation of each stock. Note: Do not round intermediate calculations. Round your answer to 1 decimal place