| Robert Gibson, James Ryan - 1839 - 412 páginas
...are called irregular polygons, as an irregular pentagon, hexagon, &e. 49. Four quantities are said 10 **be in proportion when the product of the extremes is equal to that of the means** i thus if A multiplied by D be equal to B multiplied by C, then A is said to be to B as C is to D.... | |
| Olinthus Gregory - 1840 - 188 páginas
...by equal fractions, be carefully pointed out. (A.) When four numbers are direct proportionals, the **product of the extremes is equal to that of the means. Thus: — If** then, also, But Cor. Hence ad C whence the rules of proporc — -j- < . . . . . rr 6 I tion in arithmetic.... | |
| Olinthus Gregory - 1840 - 188 páginas
..." y ' since each has the same ratio to unity. (h.~) When four numbers are direct proportionals, the **product of the extremes is equal to that of the means. Thus:** — __ ad C whence the rules of propor6 1 tion in arithmetic. [Let it be remarked that the ordinary... | |
| Admiralty - 1845
...That is, if a : b and c : d be two equal ratios, as represented by the numerical equation — = — ; **then a is said to be to b, as c is to d** ; or f> d a, b, c, d are proportionals. This proportion is expressed either by a:b::c:d,ora: b=c :... | |
| Benjamin Naylor - 1850 - 324 páginas
...extreme terms, and the second and third are called the means. If four numbers be in proportion, the **product of the extremes is equal to that of the means. Thus,** 4, 7, 12, 21, are proportionals, and Extremes. Means. 21x4=12x7 If we have three terms of a proportion... | |
| Royal Military Academy, Woolwich - 1853
...95. The order of the terms of a proportion may be changed, provided that in the new arrangement the **product of the extremes is equal to that of the means. Thus** in the proportion 2 :,'!:: l<> : 15, the following arrangements may be made : — 2 : 3::10 : 15 2... | |
| J L. Ellenberger - 1854
...several ways, without altering the proportion. The test of all these transformations will be that the **product of the extremes is equal to that of the means. Thus,** since 6 : 9 = 8 : 12, or ............ t=T8r. it follows that 6 : 8 = 9 : 12\ / $ = T»T, or 12 : 9... | |
| Moffatt and Paige - 1879
...are called the extremes, and the second and third the means. When four numbers are in proportion, the **product of the extremes is equal to that of the means. Thus** in the proportion — 8 : 16 :: 9 : 18 we find that 8 X 18 = 16 x 9 = 144. In the proportion — 9:6::... | |
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