Ra"ti*o (rā"sh&ibreve;*&osl; or rā"sh&osl;),
n. [L., fr. reri, ratus, to reckon,
believe, think, judge. See Reason.] 1.
(Math.) The relation which one quantity or magnitude has
to another of the same kind. It is expressed by the quotient of the
division of the first by the second; thus, the ratio of 3 to 6 is
expressed by &frac36; or ½; of a to b by
a/b; or (less commonly) the second term is made the
dividend; as, a:b = b/a.
&fist; Some writers consider ratio as the quotient itself,
making ratio equivalent to a number.
The term ratio is also 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. See
under Rule.
2. Hence, fixed relation of number, quantity,
or degree; rate; proportion; as, the ratio of representation in
Congress.
Compound ratio, Duplicate
ratio, Inverse ratio, etc. See under
Compound, Duplicate, etc. -- Ratio of a
geometrical progression, the constant quantity by which
each term is multiplied to produce the succeeding one.
