| Gerardus Beekman Docharty - Geometry - 1867 - 474 pages
...&c. 79. Proportion is an equality of ratios. Thus, 80. Three quantities are said to be proportional when the ratio of the first to the second is equal to the ratio of the second to the third. As of the three quantities A (2), B (4), C (8), where f=f —^, both the same ratio. 81. Four quantities... | |
| 1872 - 398 pages
...8. 15. On comparing Def. 3 with Def. 1, it will be seen that when four quantities are in proportion, the ratio of the first to the second is equal to the ratio of the third to the fourth. Hence we may denote a proportion thus — 3:4 = 6:8 which is read — the ratio... | |
| William Frothingham Bradbury - Algebra - 1868 - 264 pages
...•; = -, or 6 : a. ao aba 195. PROPORTION is an equality of ratios. Four quantities are proportional when the ratio of the first to the second is equal to the ratio of the third to the fourth. The equality of two ratios is indicated by the sign of equality (=) or by four... | |
| Richard Wormell - Geometry, Modern - 1868 - 286 pages
...trouble ourselves to inquire what this unit is. Four lines are in proportion, or are proportionals, when the ratio of the first to the second is equal to the ratio of the third and fourth. Very simple geometrical constructions enable us, as we shall see, to draw four straight... | |
| James Hamblin Smith - 1869 - 412 pages
...factors of the other product must form the means. 328. Three quantities are said to be in CONTINUED PROPORTION when the ratio of the first to the second...equal to the ratio of the second to the third. Thus a, b, с are in continued proportion if a : b = b : c. . The quantity b is called a MEAN PKOPOBTIONAL... | |
| James Hamblin Smith - Algebra - 1870 - 478 pages
...the other product must form the means. 358. Three .quantities are said to be in CONTINUED PBOPOKTION when the ratio of the first to the second is equal to the ratio of the second to the third. Thus a, 6, c are in continued proportion if a : b=b :c. Four quantities are said to be in Continued Proportion... | |
| Richard Wormell - Geometry, Plane - 1870 - 304 pages
...trouble ourselves to inquire what this unit is. Four lines are in proportion, or are proportionals, when the ratio of the first to the second is equal to the ratio of the third and fourth. Very simple geometrical constructions enable us, as we shall see, to draw four straight... | |
| Elias Loomis - Geometry - 1871 - 302 pages
...consequent ; if equal, equal ; and if less, less. Def. 3. Three quantities are said to be proportional, whey the ratio of the first to the second is equal to the ratio of th<i second to the third ; thus, if A, B, and C are in proportion then A : B : : B : C. In this case... | |
| James Hamblin Smith - Algebra - 1872 - 454 pages
...factors of the other product must form the means. 358. Three quantities are said to be in CONTINUED PROPORTION when the ratio of the first to the second...equal to the ratio of the second to the third. Thus a, b, с are in continued proportion if a : 6=6 :e. The quantity 6 is called a MEAN PROPORTIONAL between... | |
| William Frothingham Bradbury - Geometry - 1872 - 124 pages
...is, 1 1 & . - -}- T = -, or o : a. aba 4, Proportion is an equality of ratios. Four quantities are in proportion when the ratio of the first to the second is equal to the ratio of the third to the fourth. The equality of two ratios is indicated by the sign of equality (=), or by four... | |
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