Opposite of Percentage
Date: 07/31/2001 at 20:45:01 From: Marty Ryerson Subject: Term for the "opposite" of percentage Hi, I am beginning to wonder if there *is* an answer to this. I am trying to write a document explaining a common procedure, namely, calculating a discounted price. To calculate the discount, you multiply the "base" by the "percent discount" to yield "percentage." At least, these were the terms I was taught. So, if the price is $32 and the discount is 15%, then you multiply 32 times .15 to get the amount that is to be subtracted from the initial price ($4.80) to yield the discounted price ($27.20). I have been taught that the "initial price" ($32) is the "base," the .15 is the "percent" or "discount rate," and the resulting discount amount ($4.80), is the "percentage." Another way to calculate the final price would be to subtract the percentage from 100 (100% - 15% = 85%) and then multiply that result by the original price (.85 times $32 = 27.20). Or, as it appears in many computer programs, net = price * (1-discount_rate), where it is understood that discount_rate is a decimal fraction. My question is one of terminology. What is the name given to the term "(1-discount_rate)" in this example? I have looked up reciprocal, complement, inverse, etc., but none of those fits. I need to be able to define this word once and then use it repeatedly in my document, rather that explaining it every time I use it, which will be many times. Thanks for any help. Marty
Date: 07/31/2001 at 22:39:23 From: Doctor Peterson Subject: Re: Term for the "opposite" of percentage Hi, Marty. What you want is "the complement of the discount rate." Here is one site I've found that defines it: Trade Discounts - Business Mathematics, Confederation College http://courses.confederationc.on.ca/bm105/part2/unit7/bm7s1.htm Trade discounts are used in the retail sector. They are used to calculate how much a retailer will pay a manufacturer for a given product... Complement of a Trade Discount: This is the difference between the discount rate and 100%. The complement can be any percent that results when you subtract the trade discount rate from 100%. In general mathematicians use the word "complement" to mean "all except ..." or "the whole minus a given part"; here it means 1 minus a fraction - though I haven't found any dictionary that gives this definition. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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