Suppose that the annual return for particular stock follows the same distribution every year, and that the return for any given year is independent of the returns for any prior years. Based on an analysis of the stock's annual returns over an 12 year period, it is determined that the 95% confidence interval for the stock's expected annual return is given by (-0.1724, 0.2861). Find the volatility of the stock. Use the approximation formula from Berk and DeMarzo. 38.52% 40.90% 42.09% 37.32% 39.71%