Hello Robert and All --
Please forgive the intrusion of a lurker in a domain above my pay
grade, as it were, but I have a slight question...
> The "Z test with s" is nothing but an unnecessary approximation of the
> t distribution for n>>1 degrees of freedom by the z distribution. The most
> that can be said for it is that if n is large it is not wrong by very
much.
>
It would seem to me that more than this most can be said. If my reading
of the central limit theorem is up to snuff, I should be able to use the "Z
test with s" without an underlying assumption of the normality of the parent
population, required for the t. I am not etching n = 30 in stone, here --
but there is _some_ large n that will make the underlying sampling
distribution of the mean sufficiently close to normal to justify the "Z with
s."
So how far off base is my understanding?
-- Chris
Chris Olsen
George Washington High School
2205 Forest Dr. S.E.
Cedar Rapids, IA 52403
(319)-398-2161
[EMAIL PROTECTED]
