What Does a Twofold Increase Mean?
Date: 01/23/2004 at 04:57:51 From: Laura Subject: 2-fold increase What does a onefold increase mean? Is a twofold increase simply twice the amount? What about a threefold increase? I'm not used to this terminology of using "fold." Does it refer to powers or multiples?
Date: 01/23/2004 at 09:40:45 From: Doctor Peterson Subject: Re: 2-fold increase Hi, Laura. The suffix "-fold" refers to multiples. "Onefold" means a whole, "twofold" means twice, "threefold" means three times as much. According to Merriam-Webster (m-w.com), "twofold" means 1 : having two parts or aspects 2 : being twice as great or as many and the suffix "-fold" means 1 : multiplied by (a specified number) : times -- in adjectives <a sixfold increase> and adverbs <repay you tenfold> 2 : having (so many) parts <threefold aspect of the problem> Although some people might quibble over "twofold increase," arguing that it has to mean the _increase_ itself is twice the original value, and thus a tripling, a quick web search makes it clear that the phrase universally refers to a mere doubling: an increase _to_ twice the original amount. See this page for a discussion of the quibble with reference to a similar, but more controversial, phrase: Percent Greater Than vs. Increased http://mathforum.org/library/drmath/view/61774.html I have never heard of a "onefold increase," and don't find the phrase on the web. If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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