THE PERCENTAGE LIMITS FOR THE DISTRIBUTION OF RANGE IN SAMPLES FROM A NORMAL POPULATION. (n ≤ 100.)

It has been assumed that the sampling distribution of range may be adequately represented bv Pearson curves with the appropriate moment-coefficients. That this assumption is not unreasonable will be seen from the experimental results presented below, but since it has had to be made, no very high degree of accuracy is justified in calculating the percentage limits frorn these curves. Nor indeed is a high degree of accuracy required for practical purposes. The procedure adopted may be summarised as follows: