[R] When normality test violate and sample size is large(n=400) can I use t-test

[Robert A LaBudde]

At 11:45 AM 6/1/2010, Kourosh Ks wrote:
>Dears
>  When normality test  violate and sample size is large(n=400) can I 
> use t-test?
>best gards kourosh

Generally "yes", unless there is something really pathological about 
the distribution.

You should note that, for n = 400, even the simplest 
distribution-free tests should have near perfect power, so which test 
you use is not important.

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Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral at lcfltd.com
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