We covered Ch. 3-3 Measures of Variation including variance (sample and population), standard deviation (sample and population), range, mean (sample and population), the Empirical Rule (1 SD from mean is 68% of the probability, 2 SD is 95%, 3 SD is 99.7%), Coefficient of Variation, biased estimators, Chebyshev's Theorem for non-normal distributions (1 SD is at least 1=1/K^2, 2 SD 75%, 3 SD 89%)