| Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...its simplest form, the proportion may be written a:b::d:c. Hence, four quantities are reciprocally proportional when the ratio of the first to the second is equal to the ratio of the fourth to the third. When the terms of each ratio of a proportion are interchanged, the four quantities... | |
| Frank Castle - Mathematics - 1900 - 184 pages
...ratios are equal, the four terms are said to be in proportion, hence : Four quantities are said to be proportional, when the ratio of the first to the second...is equal to the ratio of the third to the fourth. That is, when the first is the same multiple or sub-multiple of the second, which the third is of the... | |
| George Edward Atwood - 1900 - 276 pages
...double colon, as follows : a:b=c:d ?=£ a:b::c:d bd 416. Four numbers 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. The four numbers are called proportionals, and the fourth number is called a, fourth proportional. 417.... | |
| James Morford Taylor - Algebra - 1900 - 504 pages
...the greater ratio, 7:5 or 7 + 2:5 + 2? PROPORTION. 324. 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. An equality whose members are two equal ratios is called a proportion. Thus, if a : b = с : d, (1)... | |
| International Correspondence Schools - Sheet-metal work - 1901 - 578 pages
...the ratio 135 quarts to 63 quarts? Ans. The ratios are equal. 1.2. 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, the four numbers are said to be proportionals; and a statement of the equality of the two ratios is called... | |
| George Albert Wentworth, George Anthony Hill - Geometry - 1901 - 168 pages
...lines. EXERCISE 95. Proportion. Four quantities are said to bo proportional, or to form a proportion, if the ratio of the first to the second is equal to the ratio of the third to the fourth. The four quantities are called the terms of the proportion ; the first and the fourth are called the extremes... | |
| Metal-work - 1901 - 548 pages
...example, the three numbers 36, 18, and 9 are in continued proportion. For, we have ff = y ; that is, the ratio of the first to the second is equal to the ratio of the second to the third. In this example, 18 is the mean proportional between 30 and 9, and 9 is the third... | |
| Thomas Franklin Holgate - Geometry - 1901 - 462 pages
...is an exact multiple of the second, the second may be taken as the common unit of measure ; and then the ratio of the first to the second is equal to the measure of the first by the second. (6) RATIO OF INCOMMENSURABLE MAGNITUDES 225. Next suppose that... | |
| American School (Chicago, Ill.) - Engineering - 1903 - 426 pages
...т = — i Or о : 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...indicated by the sign of equality ( = ), or by four dots ( : : ). Thus a : b = с : d, or a : b : :c:d, ft. 1* or T = -7 ; read a to ó equal с to d, or a... | |
| Euclid - Euclid's Elements - 1904 - 488 pages
...reciprocal of A : B. Definition 9. Three magnitudes 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. Thus A, B, 0 are proportionals if A : B : i B : C. B is called a mean... | |
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