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Section 3.3

Measures of Variation

Range the difference between the maximum data value and the minimum data value; Range = (max value)-(min value) very sensitive to extreme values
Standard Deviation 's'; measure of variation of values about the mean
Variance measure of variation equal to the square of the standard deviation
Range Rule of Thumb based on the principle that for many data sets, the vast majority of sample values lie within 2 standard deviations of the mean
Usual Values typical and not too extreme (mean) - 2 x (standard deviation)
Unusual Values those which lie outside two standard deviations of the mean (mean) + 2 x (standard deviation)
Empirical (68-95-99.7) Rule data sets having a distribution that is approximately bell shaped; (68%-fall within 1 st. dev of mean; 95%-2 st dev; 99.7%-3 st dev)
Chebyshev's Theorem proportion (or fraction) of any set of data lying within K standard deviations of the mean is always at least 1-1/K^2
Created by: hfanch24