| James Thomson - 1880 - 408 pages
...Fonr numbers (or four numerics generally) constituting two equal ratios, and written in order so that **the ratio of the first to the second is equal to the ratio of the third to the fourth** (as, for instance 10, 15, 8, 12), are commonly called four proportionals. The first and last of the... | |
| Simon Newcomb - Geometry - 1881 - 418 pages
...preceding definition of a ratio gives us another definition of a proportion, namely: 354. Four magnitudes **are proportional when the ratio of the first to the...is equal to the ratio of the third to the fourth.** Thus the ratio B : A is the inverse of A : B. If A : B :: m : n, then A : B = - and B : A - - ; the... | |
| James Hamblin Smith - 1883 - 466 pages
...the other product must form the means. 358. Three quantities are said to be in CONTINUED PEOPOETION **when the ratio of the first to the second is equal to the ratio of the** second to the third. Thus a, b, c are in continued proportion if a : 6 = 6 : c. The quantity b is called... | |
| Edwin Pliny Seaver, George Augustus Walton - Algebra - 1881 - 304 pages
...7, how far from either shore will be their meeting-place ? 195. When three quantities are such that **the ratio of the first to the second is equal to the ratio of the** second to the third, the second quantity is called a mean proportional between the other two. Thus,... | |
| Alfred Hix Welsh - Geometry - 1883 - 326 pages
...three, taken in order. Thus, if a : b :: c : d, d is a fourth proportional to a, b, and c. 7. Three **quantities are proportional when the ratio of the first to the second** equals the ratio of the second to the third. Thus, a : b :: b : c. The middle term, b, is here called... | |
| Mathematical association - 1883 - 86 pages
...consequents, B, Q. DEF. 7. Three magnitudes (A, B, C) of the same kind are said to be proportionals, **when the ratio of the first to the second is equal to** that of the second to the third : that is when A : B :: B : C. In this case C is said to be the third... | |
| Ward, Lock and co, ltd - 1884 - 958 pages
...2x5x6x7:3x7x11x10, or the fraction ,* y'"^ * *Q. which-*. PBOPOBTION. When four numbers are such that **the ratio of the first to the second is equal to the ratio of the third to the fourth,** then the four numbers are said to form a proportion, or to be in proportion. The proportion is the... | |
| Homersham Cox (the younger) - 1885 - 254 pages
...contained in 10 the same number of times that 1 is in 5. If four quantities are in proportion so that **the ratio of the first to the second is equal to the ratio of the third to the fourth,** then each of these ratios will be equal to the ratio of the sum of the first and second to the sum... | |
| Edward Albert Bowser - Algebra - 1888 - 868 pages
...ratio x : y. Ans. 3 : 4. PROPORTION. 156. Definitions. — Four quantities are said to be in proportion **when the ratio of the first to the second is equal to the ratio of the third to the fourth** ; and the terms of the ratios are said to be proportionals. Thus, if - = -, then a, 6, c, d, are called... | |
| Warren H. Sadler - 1888 - 426 pages
...64? the means; 8 Ib. : 3 Ib. is the first couplet, 64? : 24? the second couplet. •1 • I O. Three **quantities are proportional when the ratio of the first to the second is equal to the ratio of the** second to the third. Thus, 8 Ib., 4 Ib., and 2 Ib. are proportional, since 8 -t- 4 = 4 -t- 2. The second... | |
| |