 | Charles Davies - Geometry - 1854 - 436 pages
...When four quantities have this relation to each other, they are said to be in proportion. To indicate that the ratio of A to B is equal to the ratio of C to D, the quantities are usually written thus, A : B : : C : D, and read, A is to B as C is to D. The quantities... | |
 | William Scott - Arithmetic - 1854 - 232 pages
...following forms : — oc ~i=j, a -• b=*c : d; a : b :: c : d, and expressed in words as follows : The ratio of a to b is equal to the ratio of c to d ; or a is to b as c is to d. c. The first and third terms of a proportion are named Antecedents, and... | |
 | George Roberts Perkins - Geometry - 1856 - 460 pages
...incommensurable magnitudes A and B are proportional to two other incommensurable magnitudes A' and B', or that the ratio of A to B is equal to the ratio of A' to B', when we obtain for each the same numerical ratio at each successive step of the approximation.... | |
 | Thomas Lund - 1856 - 198 pages
...Ratio of a to b'; hence a : b =т - Similarly с : d = -j- Therefore if т = -jj я : b — c : d, or the Ratio of a to b is equal to the Ratio of с to d. This equality of two Ratios constitutes what is called a ' PROPORTION'. It is usually written... | |
 | Joseph Ray - Algebra - 1857 - 408 pages
...equality of ratios. That is, when two ratios are equal, their terms are said to be proportional. Thus, if the ratio of a to b, is equal to the ratio of c to d, that is, if -=-, then a, b, c, d, form a proportion, and we say that a is to ac b as c is to d. Proportion... | |
 | Charles Davies - Algebra - 1860 - 330 pages
...relation to each other, compared together two and two, they are said to form a geometrical proportion. To express that the ratio of A to B is equal to the...ratio of C to D, we write the quantities thus, A : B :: C : D; and read, A is to -Z? as C to D. The quantities which are compared, the one with the other,... | |
 | Charles Davies - Algebra - 1860 - 332 pages
...expression of equality between two equal ratios. Thus, b -_ d a e' is a proportion, expressing the fact that the ratio of a to b is equal to the ratio of c to d. This proportion may also be written thus, a : b : : c : d. In either case, the proportion is read,... | |
 | George Roberts Perkins - Geometry - 1860 - 472 pages
...incommensurable magnitudes A and B are proportional to two other incommensurable magnitudes A' and B', or that the" ratio of A to B is equal to the ratio of A' to B', when we obtain for each the same numerical ratio at each successive step of the approximation.... | |
 | Euclides - 1860 - 288 pages
...the last definition, the ratio of A to C is compounded of the ratios of A to B, and of B to C ; but the ratio of A to B is equal to the ratio of B to C, because A, B, C are continual proportionals ; therefore the ratio of A to C, by this definition,... | |
 | Charles Davies - Algebra - 1861 - 322 pages
...relation to each other, compared together two and two, they are said to be in geometrical proportion. To express that the ratio of A to B is equal to the rati<< of C to D, we write the quantities thus : A : B : : C : D ; and read, A is to B as C to D. The... | |
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To express that the ratio of A to B is equal to the ratio of C to D, we write the quantities thus : A : B : : C : D; and read, A is to B as C to D. 
