 | George Roberts Perkins - 1841 - 274 σελίδες
...fourth, and four points are placed between the second and third : which is read, 4 is to 6 as 8 is to 12. The first and fourth terms of a proportion are called the extremes. The second and third terms are called the means. The first and second constitute the fast couplet.... | |
 | James Bates Thomson - 1844 - 272 σελίδες
...SECTION XIV. GEOMETRICAL PROPORTION AND PROGRESSION. ART. 337. If four quantities are in geometrical proportion, the product of the extremes is equal to the product of the means. Thus, 12 : 8 :: 15 : 10 ; therefore 12x10 = 8x15. Hence, 338. Any factor may be transferred from one of the... | |
 | William Watson (of Beverley.) - 1844 - 200 σελίδες
...proportion - = - whence xz = j/2 y ar THEOREM 2 When four numbers or quantities are in geometrical proportion, the product of the extremes is equal to the product of the means・ Thus a, b, c, d, are in geometrical ac proportion, when* - = -, or ad ・=， b c・ That is, as a 1 b 11... | |
 | Pliny Earle Chase - 1844 - 164 σελίδες
...consequents may exchange places. Thus, 2 : 6 :: 7 : 21, and 6 :2 :: 21 :7, are each true proportions. The first and fourth terms of a proportion, are called the extremes, the second and third terms, the means. The proportion 3 : 12 == 2 : 8 may also be written 735 = f .... | |
 | James Bates Thomson - 1846 - 354 σελίδες
...same ratio to the second, as the fourth has to the third. Thus 8 6 T— 5324. If four numbers are in proportion, the product of the extremes is equal to the product of the means. Thus 8 : 4 : : 6 : 3 is a proportion : for |— |. (Art. 318.) Now 8x3=4x6. Again, 12 : 6 : : £ : \ is... | |
 | James Bates Thomson - 1846 - 402 σελίδες
...ratio to the second, as the fourth has to the third. Thus 4 — £ 4 — 3' ;. If four numbers are in proportion, the product of the extremes is equal to the product of the means. Thus 8 : 4 : : 6 : 3 is a proportion : for f = f . (Art. 318.) Now 8x3 = 4x6. Again, 12 : 6 : : £ : J is... | |
 | Anna Cabot Lowell - 1846 - 216 σελίδες
...divided by BC. The first term of each ratio is called the antecedent, the second term is the consequent. The first and fourth terms of a proportion are called the extremes ; the second and third terms are the means. If the same quantity is taken twice as a mean it is called... | |
 | James S. Russell - 1847 - 340 σελίδες
...The four quantities forming a proportion are called proportionals, or, the terms of the proportion. The first and fourth terms of a proportion are called the extremes, and the second and third, the means. Also, the first terms, or divisors in ratios, are called the antecedents, and the second... | |
 | James Robinson (of Boston.) - 1847 - 304 σελίδες
...expression is usually read thus : as 5 is to 8, so is 15 to 24. Art. 138. The first and fourth numbers or terms of a proportion are called the extremes, and the second and third numbers or terms are called the means. In the other method of writing the terms, the numerator of the... | |
 | Jeremiah Day, James Bates Thomson - 1848 - 264 σελίδες
...SECTION XIV. GEOMETRICAL PROPORTION AND PROGRESSION. ART. 337. If four quantities are in geometrical proportion, the product of the extremes is equal to the product of the means. Thus, 12 : 8 :: 15 : 10 ; therefore 12x10=8x15. Hence,. 338. Any factor may be transferred from one of the... | |
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The first and fourth terms of a proportion are called the extremes, and the second and third terms are called the means, of the proportion. 
