| James Gow - Mathematics - 1884 - 350 pages
...would suffice for the discovery of many important rules, such for instance as that, in a proportion, **the product of the means is equal to the product of the extremes.** It is probable, therefore, that much of the Greek arithmetical knowledge dates from a time far anterior... | |
| Charles Davies, Adrien Marie Legendre - Geometry - 1885 - 538 pages
...product is a fixed quantity, as xy = m. PROPOSITION I. THEOREM. If four quantities are in proportion, **the product of the means is equal to the product of the extremes.** Assume the proportion, BD A : B : : C : D ; whence A" = ~C- ' clearing of fractions, we have, BC =... | |
| Frederick John Gladman - Classroom management - 1885 - 320 pages
...— the four numbers are in " proportion." 2 : 4 : : 3 : 6 (b) When four numbers are in proportion, **the product of the means is equal to the product of the extremes.** Define the terms "means" and "extremes," and illustrate the truth of the dictum by an example. In every... | |
| Homersham Cox (the younger) - 1885 - 248 pages
...means. But whichever way it is written the theorem just proved can be stated thus— In any proportion **the product of the means is equal to the product of the extremes.** Since the product of 10 and 15 is equal to the product of 25 and 6 they both have the same ratio to... | |
| Research & Education Association Editors, Ernest Woodward - Mathematics - 2012 - 1080 pages
...angles. 10. AA = AA 11. Corresponding sides of similar triangles are in proportion. 12. In a proportion, **the product of the means is equal to the product of the extremes.** • PROBLEM 531 Using Ptolemy's Theorem show that if a anS b, with a ^ b, are chords of two arcs of... | |
| Ann Faber, Gale Edgerton, Paul Karanevich - Mathematics - 1985 - 254 pages
...proportion amounts to multiplying the "means" (inner numbers) and the "extremes" (outer numbers). If **the product of the means is equal to the product of the extremes,** the ratios are equal. 2X2 = 4 1:2 2:4 1 X4 = 4 4 = 4, so that 1 :2 = 2:4 is a proportion. I Example... | |
| Research and Education Association - Mathematics - 2015 - 112 pages
...the means of the proportion. The single term d is called the fourth proportional. In a proportion, **the product of the means is equal to the product of the extremes.** Theorem 2 A proportion may be written by inversion. (If alb = eld, then bla = die.) Theorem 3 •i... | |
| Joanne K. Price - Technology & Engineering - 1991 - 378 pages
...proportion. The inside terms (2nd and 3rd) are called the means of a proportion. For all proportions, **the product of the means is equal to the product of the extremes.** In other words, when the two inside terms are multiplied, the answer will be the same as when the two... | |
| Brian Burrell - Mathematics - 1998 - 386 pages
...The resulting proportion is .*-.-! 18 ~ 3 This can be solved by cross-multiplication. (Recall that **the product of the means is equal to the product of the extremes.)** Thus 3x = 18 - 4 = 72, and therefore x = 7% = 24. doubled, the volume of the cube increases by a factor... | |
| Haym Kruglak, John Moore, Ramon Mata-Toledo - Mathematics - 1998 - 508 pages
...proportion. The above proportion can be written in fractional form as a/b = c/d. Rule. In any proportion, **the product of the means is equal to the product of the extremes.** Ratio For instance, 3:4 = 6:8 is a proportion and the product of the means is (4)(6) or 24 and the... | |
| |