The term "range" has two completely different meanings in statistics. Given order statistics Y_1 = min_j X_j, Y_2, ..., Y_(N - 1), Y_N = max_j X_j, the range of the random sample is defined by R congruent Y_N - Y_1 (Hogg and Craig 1995, p. 152). For small samples, the range is a good estimator of the population standard deviation (Kenney and Keeping 1962, pp. 213-214).

midrange | range | statistical median