R help - Aug 2005 - chisq.test

Hi
 
I am trying to use this function.  Can anyone show me how I would input
the following example?
 
Chi-Squared = (40-30)^2 + (20-30)^2 + (30-30)^2
                           30           30             30
 
= 3.333 + 3.333 + 0 = 6.666 (p value = 0.036)
 
I want to be able to use different denominators so can you show me how I
can do it to accommodate these rather than assuming they are all the
same.
 
Thanks.
 
Stephen

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"Stephen Choularton" <mail at bymouth.com> writes:
> Hi
>  
> I am trying to use this function.  Can anyone show me how I would input
> the following example?
>  
> Chi-Squared = (40-30)^2 + (20-30)^2 + (30-30)^2
>                            30           30             30
>  
> = 3.333 + 3.333 + 0 = 6.666 (p value = 0.036)
> chisq.test(c(40,30,20))
        Chi-squared test for given probabilities

data:  c(40, 30, 20)
X-squared = 6.6667, df = 2, p-value = 0.03567
>  
> I want to be able to use different denominators so can you show me how I
> can do it to accommodate these rather than assuming they are all the
> same.
 No. You want to test different *hypotheses* about the distribution on
 the three groups. E.g. for 2:1:1 split:
> chisq.test(c(40,30,20),p=c(.5,.25,.25))
        Chi-squared test for given probabilities

data:  c(40, 30, 20)
X-squared = 3.3333, df = 2, p-value = 0.1889
 

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