Assuming that future one-day returns for A and B have the same variances and covariance observed in this sample, find the standard deviation of one-day returns for a portfolio with weight 0.75 on A and 0.25 on B. consider all possible portfolios with weight w on A and 1 w on B. For what w is the variance of one-day portfolio returns the smallest? What is the standard deviation of one-day returns for this portfolio? (Hint: you can solve this by using Solver in Excel or manually deriving the optimal weight.) Weight w with minimum portfolio variance? Portfolio standard deviation .