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What is the best way to cacluate the inverse of a percentage? For example:

100 * .85 = 85 85 * x = 100 x = 100 / 85 x = 1.17647 

Also,

279 * .85 = 237.15 237.15 * x = 279 x = 279 / 237.15 x = 1.17647 

For any percentile y (i.e. .85), how do I cacluate its inverse (i.e. 1.17647)? Is the best way to just choose arbitrary numbers (operands) as I've done above? Or is there a more elegant solution?

1 Answers 1

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Simply calculate its multiplicative inverse by definition: for a non-zero real number $y$, $y^{-1} = \frac 1y.$

E.g., set your initial value to 1:

1 * . 85 = .85 .85 * x = 1 x = 1 / .85 x = 1.17647 
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    Yeah, I guess I was just overthinking (or perhaps underthinking) it. But thanks, your answer makes sense.2011-07-04