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Re: Chi Square Areas

• To: mathgroup at smc.vnet.net
• Subject: [mg110914] Re: Chi Square Areas
• From: Ray Koopman <koopman at sfu.ca>
• Date: Sun, 11 Jul 2010 06:20:08 -0400 (EDT)
• References: <i199d5$q45$1@smc.vnet.net>

On Jul 10, 1:01 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.

In[1]:= {df = 8, p = .05, 2 InverseGammaRegularized[df/2, p]}

Out[1]= {8, 0.05, 15.5073}

In[2]:= {df = 5, p = .1, 2 InverseGammaRegularized[df/2, p]}

Out[2]= {5 ,0.1, 9.23636}