4. (This problem is inspired by Berk and DeMarzo 11.16.) Suppose that each stock has a volatility of 40%, and the correlation between pairs of stocks is 25% a. Estimate the volatility of an equally weighted portfolio with i) 1 stock ii) 10 stocks iii) 100 stocks iv) 1000 stocks. b. Using a spreadsheet program, create a chart of the volatility of the portfolio for equally weighted portfolios of size 1 stock to 100 stocks (consider using the Excel function SORT). Make sure your chart has a title, titles for the axes, and is generally readable. c. Calculate the minimum volatility for an equally weighted portfolio of arbitrary size. Compare to your chart