# Skewness

Skewness is a statistic that is used to measure the symmetry of the distribution for a set of data. The skewness of an analysis domain is calculated as follows:

Skewness = K3 / ESD 3

where:

K3 = [n · Σi (Ei - En)3] / [(n-1)·(n-2)] if n 3;

K3 = 0 if n < 3

summation is over all samples i in the region

n is the number of samples included in the summation. Ei is the linear Sv of sample i (m2/m3) - set to 0 for any sample where Ei < mSv or Ei > MSv, En is the observed Mean Energy of the region in linear units (m2/m3) = 10Sv/10 mSv is the minimum integration threshold (dB re 1 m-1) at time of processing. MSv is the maximum integration threshold (dB re 1 m-1) at time of processing. ESD Standard_deviation (Standard Deviation of the Energy)

All symbols are as defined in the nomenclature developed for SHAPES algorithms.

#### See also

About skewness

School Detection module algorithms

Other region variables for schools analysis