Two stocks are available. The corresponding expected rates are r₁ and r₂; the corresponding variances and covariances are ₁², ₂², and ₁₂. What percentages of total investment should be invested in each of the two stocks to minimize the total variance of the rate of return of the resulting portfolio? What is the mean rate of return of this portfolio?

Two stocks are available. The corresponding expected rates are r1 and r2; the corresponding variances and covariances are sigma12, sigma22, and sigma12. What percentages of total investment should be invested in each of the two stocks to minimize the total variance of the rate of return of the resulting portfolio? What is the mean rate of return of this portfolio