After discussing the mathematical conditions a cumulative curve must satisfy, and some conceivable possibilities of approximating these curves with elementary functions, the authors describe a numerical method of obtaining cumulative curves by interpolation with polynomials, based on Lagrange's formula. From the cumulative curves, the frequency curves and statistical data are computed. The results are obtained in form of tables. Another method has been developed for statistical analysis of a deposit. This method is designed to compute and compare the statistical measures, in interval for interval, in a number of samples. To illustrate these methods, size frequency distributions of rock chippings obtained by jackhammer borings through a weathered fault zone, and variations of a deposit of coarse gravel are briefly discussed.