measures of skewness

     Skewness is the measure to study the aspect of whether a distribution is symmetrical or not if a distribution is not symmetrical we say that it is skewed. In a symmetrical distribution the values of the variable equi-distant from their mean have equal frequencu.

     In a perfectly symmetrical distribution mean, median and mode coincide if this is not the case the distribution is said to be skewed.


pearson's coefficient of skewness = mean-mode
                                                      ------------
                                                        S.D



when mode is not well defined

pearson's coefficient of skewness = 3(mean-median)
                                                   -------------------------
                                                         S.D


Bolwey's coefficient of skewness = Q3+Q1-2M
                                                      ------------------
                                                              Q3-Q1