 | Jeremiah Day - Algebra - 1820 - 352 pages
...then a—bs=b—c And transposing —b and — c, a+c=26. GEOMETRICAL PROPORTION. 374. But if four quantities are in geometrical proportion., the PRODUCT of the extremes is equal to the product of the means. If a : b : : c : d, ad=bc ac For by supposition, (Arts. 346, 364.) y =—... | |
 | Jeremiah Day - Algebra - 1827 - 352 pages
...— b=b — c S And transposing - 6 and — c, ' o+c— 26. GEOMETRICAL PROPORTION. 374. But if four quantities are in geometrical proportion, the PRODUCT of the extremes is equal to the product of the meant. If a : b'. '.c : d, ad=bc For by supposition, (Arts. 346, 364.) -=bd Multiplying... | |
 | James Bates Thomson - Algebra - 1844 - 272 pages
...585. What are the numbers 1 SECTION XIV. GEOMETRICAL PROPORTION AND PROGRESSION. ART. 337. If four quantities are in geometrical proportion, the product...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 means... | |
 | James Bates Thomson - Algebra - 1844 - 266 pages
...numbers 1 » \ /.-•/.' * ' 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 tht means. Thus, 12 : 8:: 15 : 10 ; therefore 12x10=8x15. Hence, 338. Any factor... | |
 | James Bates Thomson - Arithmetic - 1846 - 354 pages
...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 - Arithmetic - 1846 - 402 pages
...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... | |
 | Jeremiah Day - Algebra - 1847 - 358 pages
....e, then, ab=b — c And transposing - b and - c, a+c= 26. GEOMETRICAL PROPORTION. 374. But if four quantities are in geometrical proportion, the PRODUCT of the extremes is equal to the product of the meant. If a:b::c:d, ad=lc For by supposition, (Arts. 346, 364.) -=bd Multiplying... | |
 | Jeremiah Day, James Bates Thomson - Algebra - 1848 - 264 pages
...585. What are the numbers 1 SECTION XIV. GEOMETRICAL PROPORTION AND PROGRESSION. ART. 337. If four quantities are in geometrical proportion, the product...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... | |
 | Stephen Chase - Algebra - 1849 - 348 pages
...proportion. ak §232. Let a: b = k : I, or r — T. o I Clearing of fractions, al=bk. That is, In any proportion, the product of the extremes is equal to the product of the means. Thus, if 5 : 7 = 10 : 14, then 5X14 = 10X7. Hence, a. Cor. i.) If any three terms of a proportion be given,... | |
 | Charles Guilford Burnham - 1850 - 350 pages
...may be repeated, so as to form the two terms. Thus, 6 : 12 :: 12: 24. Art, 168. — If four numbers are in geometrical proportion, the product of the...extremes is equal to the product of the means. Thus, 12 : 8 : : 15 : 10, for 12 x 10 = 8 x 15. Art, 169, — By multiplying the extremes and means together,... | |
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In every proportion the product of the extremes is equal to the product of the means. Thus, in the proportion 3 : 5 : : 6 : 10 we have 3 X 10 = 5 X 6. 
