2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28955A length dependence of the effective mobility in the form of a power law, B ~ L^(1-1/alpha) is observed in dispersive transport in amorphous substances, with 0 < α< 1. We deduce this behavior as a simple consequence of the statistical theory of extreme events. We derive various quantities related to the largest value in samples of n trials, for the exponential and power-law probability densities of the individual events.13 pages, 3 Postscript figuresStatistical Mechanicstext