What is "ultimate ratio"

Ultimate \Ul"ti*mate\, a. [LL. ultimatus last, extreme, fr. L. ultimare to come to an end, fr. ultimus the farthest, last, superl. from the same source as ulterior. See Ulterior, and cf. Ultimatum.]

1. Farthest; most remote in space or time; extreme; last; final.

   My harbor, and my ultimate repose.
   --Milton.

   Many actions apt to procure fame are not conductive to this our ultimate happiness.
   --Addison.

2. Last in a train of progression or consequences; tended toward by all that precedes; arrived at, as the last result; final.

   Those ultimate truths and those universal laws of thought which we can not rationally contradict.
   --Coleridge.

3. Incapable of further analysis; incapable of further division or separation; constituent; elemental; as, an ultimate constituent of matter.

   Ultimate analysis (Chem.), organic analysis. See under Organic.

   Ultimate belief. See under Belief.

   Ultimate ratio (Math.), the limiting value of a ratio, or that toward which a series tends, and which it does not pass.

   Syn: Final; conclusive. See Final.