1. The distribution of annual returns on common stocks is roughly symmetric, but extreme observations are somewhat more frequent than in Normal distributions. Because the distribution is not strongly non-Normal, the mean return over a number of years is close to Normal. Historically, annual returns on common stocks (not adjusted for inflation) have varied with mean about 13% and st ndard deviation about 17%. Andrew plans to retire in 45 years. He assumes (this is dubious) that the past pattern of variation will continue. What is the probability that the mean annual return on common stocks over the next 45 years will exceed 15%? what is the probability that the mean return will be less than 7%