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I am not a native speaker, so I was always under impression that "factor of K larger" means something was X and became K * X (e.g. the multiplicative factor was
by mraleph 9y ago
I am not a native speaker, so I was always under impression that "factor of K larger" means something was X and became K * X (e.g. the multiplicative factor was 1 and became X). Can I read somewhere about the correct usage?
- IncRnd 9y agowww.wikihow.com/Calculate-Percentage-Increase The general equation for an increased quantity from A to B is increase = B - A So a percentage increase is increase * 100 not (increase + A) * 100
- mraleph 9y agobut I am not talking about the percentage increase I am talking about increase "by a factor of X" that is X = B/A. See: https://ell.stackexchange.com/a/52747 https://ell.stackexchange.com/a/52747 Maybe my problem is that I am missing "by".
- IncRnd 9y agoYou are exactly talking about percentages. B/A is the percentage of the new value relative to the old. (B-A)/A is the percentage of the increase of the value. This is algebra not English. 1) You start out with one rock. 2) You add another rock, getting a pile of two rocks. 3) The rock pile size is now 200% of the original size. But, the increase of the rock pile size is 100%. 4) According to the rules of algebra, 100% = 1. In this case 100% = 1 rock, since the unit under discussion is rocks.
- neurotrace 9y agoThey absolutely are not talking about percentages. They're talking about factors. A factor is a term in a multiplication. In standard US English, increasing something by a factor means to multiply it by that number. Even the GMAT uses that phrase in that way. You absolutely can split hairs on this and the phrasing can be confusing but it is absolutely understood that "increased by a factor of 4" means to multiply by 4. If one was talking in terms of percentages, they would say something like "increased by 300%".
- IncRnd 9y ago>* increasing something by a factor means to multiply it by that number* That's absolutely wrong... When you multiply something you scale it by a factor. When you add to something you increase it. 1) 4A is 400% of A. 2) 4A in an increase of 300%. 3) 4A is an increase of 3A. 4) 4A is an increase of a factor of 3. In the most charitable interpretation you are confusing the terms of exponential growth with linear scaling and misapplying from one to the other. A growth factor is not the same as an increase in a factor.
- neurotrace 9y agoGo ahead and tell that to everyone who has been using that phrase to mean what I describe. I seriously searched for a single case of someone using the phrase in the manner you're insisting is correct and came up empty. Instead, I found a large number of resources backing up what I and OP have been stating. Even many professional mathematicians acknowledge the ambiguity but agree that the phrase means to multiply. You may disagree with how the phrase came to be but it clearly has been taken to mean to multiply. https://www.beatthegmat.com/word-translation-when-x-increases-by-a-factor-of-4-t112477.html https://www.beatthegmat.com/word-translation-when-x-increase... https://www.quora.com/Mathematics-What-does-it-mean-to-increase-something-by-a-factor-10 https://www.quora.com/Mathematics-What-does-it-mean-to-incre... https://www.macmillandictionary.com/us/dictionary/american/by-a-factor-of-something https://www.macmillandictionary.com/us/dictionary/american/b... http://mathforum.org/library/drmath/view/74439.html http://mathforum.org/library/drmath/view/74439.html https://ell.stackexchange.com/questions/52706/what-does-reduce-by-a-factor-of-10-mean-in-terms-of-percentage-in-the-followin https://ell.stackexchange.com/questions/52706/what-does-redu... https://www.physics.uoguelph.ca/tutorials/exp/factor.html https://www.physics.uoguelph.ca/tutorials/exp/factor.html
- IncRnd 9y agoThanks for posting the first few links from using Google. Here are some other links from Google that explains why your vociferous insistence is wrong. http://www.crackssat.com/isee/word-problems/question-250-answer-and-explanation.html http://www.crackssat.com/isee/word-problems/question-250-ans... https://english.stackexchange.com/questions/8680/how-much-exactly-is-increased-when-it-is-increased-by-1-1 https://english.stackexchange.com/questions/8680/how-much-ex... https://forum.wordreference.com/threads/increase-by-a-factor-of-3-5.3358039/ https://forum.wordreference.com/threads/increase-by-a-factor... https://books.google.com/books?id=wDKLXdzQL5AC&pg=PA182&lpg=PA182&dq=math+definition+%22increase+by+a+factor%22&source=bl&ots=ErH2OhIR8J&sig=N1Pvv2qZOrl5kt3xsjwJJjjWV7Q&hl=en&sa=X&ved=0ahUKEwiytqf1wsvZAhULzlkKHZovCN84ChDoAQgmMAA#v=onepage&q=math%20definition%20%22increase%20by%20a%20factor%22&f=false https://books.google.com/books?id=wDKLXdzQL5AC&pg=PA182&lpg=... http://econlog.econlib.org/archives/2010/05/the_wall_street.html http://econlog.econlib.org/archives/2010/05/the_wall_street.... In addition to the short explanation in the last link, some of the comments on that page may help shed light, such as: I'm a college student, and for the past few years I've been an SAT tutor to pay the bills. 95% of my students do not know how to calculate percentage change. I spend hours teaching kids this. They usually start to get it after working with the formula several times, and then I show them this: for any number "n" 100% increase = n*2 = double 200% increase = n*3 = triple 300% increase = n*4 = quadruple ... x*100% increase = n*(x+1) When math is being discussed, even simple math, I'm going to go with the mathematical explanation not the arguments of populism. That's especially true for this case, where people are corrected in school and out of school constantly for the mistake you are promulgating.
- IncRnd 9y agoI forgot the division in that post, and I can't edit it. See the post below. Sorry.