2. Which one of the following portfolios cannot lie on the efficient frontier as described by Markowitz? Please explain your answer. Portfolio Expected return (%) Standard deviation (%) W 15 X 12 15 Y 5 7 Z 21 3. Suppose all stocks have E(A) = 15%, 5 = 60%, and common correlation coefficient p = 0.5. What are the expected return and standard deviation of an equally weighted portfolio of n = 25 stocks? 4. Refer to question (). What is the smallest number of stocks necessary to generate a portfolio with standard deviation of at mud 43%? 5. Refer to question (3). As a gets larger, is it true that a = app ? Please explain your