In-class exercise on Population distributions, sampling distributions, and confidence intervals Each student surveys (at random) eight classmates for their shoe size (If you are uncomfortable revealing the truth, then lie.) Calculate the average of the first 4 people surveyed. Calculate the average of the first 8 people surveyed. Report to the professor a. Your shoe size b. n=4 average c. n=8 average We should observe that the population is not normal The sampling distribution n=4 is close to normal the sampling distribution is even closer to normal The standard error for the sampling distributions (the standard deviation of the sample averages) is approximately the pop stdev /sqrt(n).