 | James Bryce - Algebra - 1837 - 322 pages
...whence we easily find 4. Given, — £— : — ^ — : : 7 : 4, to find ». Since, in a proportion, the product of the means is equal to the product of the extremes (Eue. VI. 16), it follows that 126—7х 10х+8= - 4 - O2 By multiplication, 40 x +32 =126—... | |
 | Arithmetic - 1838 - 218 pages
...rule of three is derived.. In the following proportions the pupil will perceive that in every case the product of the means is equal to the product of the extremes. As 2 : 4 :: 6 : 12 2 : 8 :: 5 : 20 3 : 5 :: 6 : 10 7 : 11 :: 14 : 22 , Now suppose that we... | |
 | George Willson - Arithmetic - 1838 - 194 pages
...geometrical proportion consisting of four terms, have been explained on page 92, and the reason assigned why the product of the means is equal to the product of the extremes. This equality between their products suggests an obvious method of finding any term of a... | |
 | George Willson - Arithmetic - 1838 - 194 pages
...geometrical proportion consisting of four terms, have been explained on page 92, and the reason assigned why the product of the means is equal to the product of the extremes. This equality between their products suggests an obvious method of rinding any term of a... | |
 | Thomas H. Palmer - Education - 1840 - 328 pages
...contains, or is contained, in the consequent of the second ; and, from this equality, it follows, that the product of the means is equal to the product of the extremes. For, if the numbers of the second ratio be double (treble, one half, or any other number... | |
 | Joseph Denison - Mechanics - 1841 - 210 pages
...by one of the inclined sides ; that is, P = — S TT By theorem 1, P ; R ; ; — ; S ; and because the product of the means is equal to the product of the extremes, PS=R|; and dividing each of these equals by S, K! From theorem 2 we derive the following... | |
 | Joseph Denison - Mechanics - 1841 - 210 pages
...= —•; one value of V. Solution 2.—By the third expression, v \ V ; ; - ; —. * i And because the product of the means is equal to the product of the extremes, and dividing by -, V = (4) "OT ; second value of V, by the third expression (which is here... | |
 | Thomas Sherwin - Algebra - 1842 - 326 pages
...d, we have ad = b c. But a and d are the extremes, and 6 and c the means. Hence, In any proportion the product of the means is equal to the product of the extremes. 2. Suppose we have ad = bc. Dividing both members by 6 and d, we have r = -, or a : b = c... | |
 | John Darby (teacher of mathematics.) - 1843 - 236 pages
...T8T, and they are equal ; that is 4 : 6 :zz 8 : 12, Therefore £ = TV Whence 4x12:=eX8. In Proportion, the product of the means is equal to the product of the extremes; therefore 4 : 6 :: 8 : 12. In this proportion the 4 and 12 are the extremes, and the 6 and... | |
 | Nicholas Tillinghast - Geometry, Plane - 1844 - 110 pages
...products thus, (6+3+10). 4. (Explanation of Signs, 6). Prop. 1. When four numbers are in proportion, the product of the 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... | |
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In any proportion, the product of the means is equal to the product of the extremes. 
