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#1 2013-05-01 10:02:56

ladyrain95
Member
Registered: 2013-05-01
Posts: 1

Z-Scores

I am at college level "Math For Liberal Arts".. we are in our last chapter and it's Statistics:

Find the z-score that best satisfies the condition.

14% of the total area is to the left of z.



I thought I understood the basics of this, but I'm frustrated and really confused. Anytime I have to find a number from the "Areas Under the Standard Normal Curve" chart I get the wrong number. I don't know what I'm doing wrong.. can someone please help me?

Last edited by ladyrain95 (2013-05-01 10:11:28)

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#2 2013-05-01 10:48:32

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,162

Re: Z-Scores

Hi;

http://easycalculation.com/statistics/p … -score.php

Enter in 14 and left tailed and out pops -1.08.

Or use the table here.

http://math2.org/math/stat/distributions/z-dist.htm

It is for below ( to the left ) of a z score. Look for .14. You will find it in row (-1) and column (.08). Answer again is -1.08 standard deviations.

A quick math check:


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#3 2013-05-02 00:11:56

stapel
Member
Registered: 2006-07-22
Posts: 15

Re: Z-Scores

ladyrain95 wrote:

I thought I understood the basics of this, but...Anytime I have to find a number from the "Areas Under the Standard Normal Curve" chart I get the wrong number. I don't know what I'm doing wrong.. can someone please help me?

In order to help you figure out what you're doing wrong, you'll need to tell us what you're doing. Please reply with your steps and reasoning. Thank you! wink

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