Suppose that the percentage returns for a given year for all stocks listed on the New York Stock Exchange are approximately normally distributed with a mean of 12.4 percent and a standard deviation of 20.6 percent. Consider drawing a random sample of n ô°‚ 5 stocks from the population of all stocks and calculating the mean return, x, of the sampled stocks.
Find the mean and the standard deviation of the sampling distribution of x, and find an interval containing 95.44 percent of all possible sample mean returns.