We report on a study of the ratio of inclusive three-jet to inclusive two-j
et production cross sections as a function of total transverse energy in p
(p) over bar collisions at it center-of-mass energy roots = 1.8 TeV, using
data collected with the DO detector during the 1992-1993 run of the Fermila
b Tevatron Collider. The measurements are used to deduce preferred renormal
ization scales in perturbative O(alpha (3)(s)) QCD calculations in modeling
soft-jet emission.