a) A portfolio consisting of Stocks 1 and 2 has an expected return of 13%. What is the standard deviation of this portfolio given the information about Stocks 1 and 2 in Table 4.1?

a) A portfolio consisting of Stocks 3 and 4 has zero variance. What is the weight of Stock 3 in this portfolio given the information about Stocks 3 and 4 in Table 4.2?