Done in excel if possible. Thank you very much!

Suppose that the standard deviation of returns for a typical share is about .4 (or 40%) a year. Assume the correlation between the returns of each pair of shares is about.3. a) Calculate the variance and standard deviation of the returns on a portfolio that has equal investments in two shares, three shares, and so on, up to 10 shares. b) Use your estimates to draw a graph with number of shares on the x-axis, the standard deviation on the y-axis. What is the underlying market risk that cannot be diversified away? c) Repeat (a) and (b) given a correlation of 0. Suppose that the standard deviation of returns for a typical share is about .4 (or 40%) a year. Assume the correlation between the returns of each pair of shares is about.3. a) Calculate the variance and standard deviation of the returns on a portfolio that has equal investments in two shares, three shares, and so on, up to 10 shares. b) Use your estimates to draw a graph with number of shares on the x-axis, the standard deviation on the y-axis. What is the underlying market risk that cannot be diversified away? c) Repeat (a) and (b) given a correlation of 0