5.3 Skewness and Kurtosis

　

Skewness - Measure of relative symmetry. Zero indicates symmetry. The larger its absolute value the more asymmetric the distribution. Positive values indicate a long right tail, and negative values indicate a long left tail. Skewness = 0 　 Skewness > 0 　 Skewness < 0

Kurtosis - Measure of the relative peakedness of a distribution. K = 3 indicates a normal “bellshaped” distribution (mesokurtic). K < 3 indicates a platykurtic distribution (flatter than a normal distribution with shorter tails). K > 3 indicates a leptokurtic distribution (more peaked than a normal distribution with longer tails). K = 3 indicates a normal “bellshaped” distribution (mesokurtic). 　 K < 3 indicates a platykurtic distribution. 　 K > 3 indicates a leptokurtic distribution. 　 Number of modes = 2 indicates a bimodal distribution.

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