From the method of moments, Pearson established four parameters for curve-fitting to show how the data clustered (the mean), how it spread (the standard deviation), if there were a loss of symmetry (skewness) and if the shape of the distribution were peaked or flat (kurtosis). These four parameters describe the essential characteristics of any distribution: the system is parsimonious and elegant. These statistical tools are essential for interpreting any set of statistical data, whatever shape the distribution takes.
