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Re: Chi Square Areas

• To: mathgroup at smc.vnet.net
• Subject: [mg110922] Re: Chi Square Areas
• From: Norbert Marxer <marxer at mec.li>
• Date: Sun, 11 Jul 2010 06:21:36 -0400 (EDT)
• References: <i199d5$q45$1@smc.vnet.net>

On Jul 10, 10:01 am, Steve <s... at epix.net> wrote:
> Hi,
>
> Can someone show me how to get Mathematica to provide the areas to the
> right of a given critical value of the Chi Square distribution ?
>
> The table entries shown athttp://www2.lv.psu.edu/jxm57/irp/chisquar.html
> are what I need to compute.
>
> For example, given 8 degrees of freedom and a probability value of
> 0.05 the result would be 15.51.
>
> And given 5 degrees of freedom with probability 0.1 the result is
> 9.24.
>
> How can I produce these results in Mathematica ?
>
> Thanks so much.

Hello

You can use the built-in functions:

InverseCDF[ChiSquareDistribution[8], 0.95]
InverseCDF[ChiSquareDistribution[5], 0.9]

which will give you the numbers 15.5073 and 9.23636.

But note, these numbers represent the critical values! The areas (to
the right) are given by 0.05 (5%) and 0.10 (10%) respectively.

Best Regards
Norbert Marxer