how to determine if skewness is normal
The variance of the skewness of a random sample of size n from a normal distribution is. An approximate alternative is 6/ n, but this is inaccurate for small samples. In normal samples, has the smaller variance of the two estimators, with. where m 2 in the denominator is the (biased) sample second central moment.f the distribution is symmetric, then the mean is equal to the median, and the distribution has zero skewness. If, in addition, the distribution is unimodal, then the mean = median = mode.