 | Nicholas Tillinghast - Geometry, Plane - 1844 - 108 pages
...means is equal to the product of the extremes ; as, 6 : 4 : : 15 : 10, hence 10.6=15.4. Prop. 2. If the product of two numbers is equal to the product of two other numbers, the four may be arranged in a proportion ; as, 8.3=12.2, hence 8 : 12 : : 2 : 3. Scholium. Remark that... | |
 | Bourdon (M., Louis Pierre Marie) - Arithmetic - 1858 - 262 pages
...multiplication, they must have been equal at first. Hence the property is proved. 161. Reciprocally. — If the product of two numbers is equal to the product of two other numbers, these four numbers form a proportion of which either pair of factors will constitute the means, the... | |
 | William Chauvenet - Geometry - 1871 - 380 pages
...mean proportional between two numbers is equal to the square root of their product. 6. Conversely, if the product of two numbers is equal to the product of two others, either two may be made the extremes, and the other two the means, of a proportion. For, if... | |
 | William Chauvenet - Geometry - 1872 - 382 pages
...mean proportional between two numbers is equal to the square root of their product. 6. Conversely, if the product of two numbers is equal to the product of two others, either two may be made the extremes, and the other two the means, of a proportion. For, if... | |
 | Richard Wormell - 1876 - 268 pages
...mark the fourth term by x — 12 : 108 : : n : x. And from what has already been said — («). When the product of two numbers is equal to the product of two othtrs they form a proportion in four different ways. Thus the four numbers (5, 54, 6, 45) form a proportion... | |
 | William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...proportional (II., 36) between two numbers is equal to the square root of their product. 6, Conversely, if the product of two numbers is equal to the product of two others, either two may be made the extremes, and the other two the means, of a proportion. For, if... | |
 | George Albert Wentworth - Algebra - 1888 - 514 pages
...are given, it appears from the above that the fourth term can have one, and but one, value. 191. If the product of two numbers is equal to the product of two others, either two may be made the extremes of a proportion and the other two the means. For, if ad... | |
 | William Frothingham Bradbury, Grenville C. Emery - Algebra - 1889 - 444 pages
...product of the means. Let a : b = с : d that is, т = -, о а Clearing of fractions, ad=bc 311. If the product of two numbers is equal to the product of two others, the factors of either product may be made the extremes, and the factors of the other the means,... | |
 | George Albert Wentworth - Algebra - 1891 - 550 pages
...are given, it appears from the above that the fourth term can have one, and but one, value. 280. If the product of two numbers is equal to the product of two others, either two may be made the extremes of a proportion and the other two the means. For, if ad... | |
 | George Albert Wentworth - Algebra - 1891 - 380 pages
...are given, it appears from the above that the fourth term can have one, and but one, value. 315. If the product of two numbers is equal to the product of two others, either two may be made the extremes of a proportion and the other two the means. For, if ad... | |
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If the product of two numbers is equal to the product of two other numbers, either pair may be made the means, and the other pair the extremes, of a proportion. 
