Ra'ti-o, n.
(rā'shĭ-o, or rā'sho), n. [Lat., from reri, ratus, to reckon, to believe, think, judge. See REASON.]
Sense 1. (Math.) The relation which one quantity or magnitude has to another of the same kind, as expressed by the quotient of the second divided by the first; thus, the ratio of 3 to 6 is expressed by ⁶⁄₃, or 2; of a to b, by b⁄a.
☞ Some writers, less properly, consider ratio as the quotient of the first quantity divided by the second. The term ratio is sometimes applied to the difference of two quantities, as well as to their quotient, in which case the former is called arithmetical ratio, the latter geometrical ratio. The name ratio is sometimes given to the rule of three, in arithmetic.
Sense 2. Hence, fixed relation of number, quantity, or degree; rate; proportion; as, the ratio of representation in Congress.
Ratio of a geometrical progression, the constant quantity by which each term is multiplied to produce the succeeding one. Math. Dict.