Adding (or subtracting) a constant to a group of observations results in adding (or subtracting) the same constant to the arithmetic mean but will not change the standard deviation. This provides a convenient statistical manipulation that permits simplification of the computation procedure of statistical parameters of grain-size distribution of sediments. The phi mean and phi standard deviation (and also skewness and kurtosis) are computed directly from the sieve screen size and weight frequencies.

First Page Preview

First page PDF preview
You do not currently have access to this article.