Check my work 1 Problem 8-5 10 A portfolio management organization analyzes 64 stocks and constructs a mean-variance efficient portfolio using only these 64 securities. points a. How many estimates of expected returns, variances, and covariances are needed to optimize this portfolio? eBook Print References Estimates expected retums Estimates of variances Estimates of covariances Total estimates b. If one could safely assume that stock market returns closely resemble a single-index structure, how many estimates would be needed? Estimates