i need with this please

Using the following 3 securities calculate: 1. Expected return 2. Variance 3. Standard deviation Correlation between all possible pairs S. Covariance between all possible pairs 4. Probability Stock A Stock B Stock C .30 8% 35% 4 % 30 12% 25% 10% 20 8% 20% 15% .20 11% 14% 16% Using the following percentages, calculate the portfolio variance, standard deviation, and expected return for each portfolio. Portfolio Stock A Stock B Stock C 1 50% 50% 2 30% 70% 3 40% 20% 40% Explain why the variance/standard deviation is less for some portfolios than the variance/standard deviation of the individual stocks that make up the portfolios. (worth 10%)