Date: Tue, 22 Dec 1998 11:40:22 GMT
Reply-To: Javier <jportela@EUCMAX.SIM.UCM.ES>
Sender: "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From: Javier <jportela@EUCMAX.SIM.UCM.ES>
Subject: Re: Still have problem with Chi Square...
Content-Type: text/plain; charset=us-ascii
>The SAS syntax to generate the probability
>of a chi-square statistic should be:
> pvalue= 1 - probchi(chi, df);
>where for this application, df=3.
>The latter syntax, swaps the position of
>the chi-sqaure varaite and the model df and
>does not subtract the obtained quantity
>A chi-square of 6.35 judged against 3 df
>has a p-value of 0.0955--not 0.1605.
>Still, the null should be rejected at
>conventional levels of statistical
probchi(df,x)=P(X<=x), were X is the random variate chi-square with df degrees
And the p-value is the probability of the "right tail area" under the
distribution, from x to infiny...
So change probchi(N-1,chi)
in the program.
(It gives P=0.838986911, not 0.0955, i do not understand Steve's result. You
should accept H0.)
Thanks, Steve, and sorry, Harvey.