A bell curve is a graph depicting the normal distribution, which has a shape reminiscent of a bell. The top of the curve shows the mean, mode, and median of the data collected. Its standard ...

S. L. Hakimi, Optimum Distribution of Switching Centers in a Communication Network and Some Related Graph Theoretic Problems, Operations Research, Vol. 13, No. 3 (May - Jun., 1965), pp. 462-475 ...