1. Explain in what sense the population variance is sensitive to small changes in a distribution.
2. For normal random variables, the probability of being within one standard deviation of the mean is .68. That is, P(µ - σ ≤ X ≤ µ + σ) = .68 if X has a normal distribution. For nonnormal distributions, is it safe to assume that this probability is again .68? Explain your answer.