2) Over the last 12 months an investment in the Vanguard Total Market Index returned 15.2 percent with a standard deviation of 31.3 percent (far more than the typical 8% return and with more risk than the historical 18% standard deviation). Assuming that the returns on this investment are normally distributed, how frequently do you expect to earn between -16.1 percent and 46.5 percent? How often do you expect to earn less than -16.1 percent