Systems of Frequency Curves Generated by Transformations of Logistic Variables.

摘要

The lognormal (S sub L, S sub B, and S sub U) systems of frequency curves are obtained by three simple transformations of the normal curve. By applying the same transformations to the logistic, systems L sub L, L sub B and L sub U are obtained. Some properties of these systems, and their relation to the S systems, are set out. Tables to facilitate fitting L sub U curves by moments are presented. (Author)