Range and Coefficient of Range

Range is the simplest measure of dispersion — the difference between the largest ($L$) and smallest ($S$) values in a data set.

• For individual and discrete series, $L$ and $S$ are simply the largest and smallest values actually observed (or, for a discrete series, the largest and smallest values of the variable $x$, ignoring frequency).
• For a continuous (grouped) frequency distribution, $L$ is taken as the upper limit of the highest class and $S$ as the lower limit of the lowest class.

Merits: simple to calculate and understand; gives a quick first idea of spread. …