Math Is Fun Forum

Xersin

Guest

Need help converting Z-scores to percents

Hi, i'm in the process of writing a program to do various statistics calculations, and wanted to know what the formula is to find the cumulative percentages that correspond to Z-scores. I've been looking all over, and every website i've ran across says nothing about a formula to find these...just the tables

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Need help converting Z-scores to percents

Hi Xersin;

-1 standard dev. to 1 standard dev. = 68.13 percent of the standard normal curve
-1.98 standard dev. to 1.98 standard dev. = 95 percent of the standard normal curve
-2.58 standard dev. to 2.58 standard dev. = 99 percent of the standard normal curve
-3 standard dev. to 3 standard dev. = 99.7 percent of the standard normal curve

http://en.wikipedia.org/wiki/Standard_score

Will give you more and the formula to calculate z.

Last edited by bobbym (2009-05-29 23:14:57)

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