Hi,
Suppose I have a data set with four variables from a market research 
survey: consumer ID, brand (say two brands, A and B), Q19 (responses to 
question 19 on a 1 - 7 scale), and a weight.  I need to compare the mean 
response on Q19 for the two brands.  With unweighted data, I would 
simply use a t test - no problem.  But with the weights I have an 
issue.  The t test does not accept weights.  If I do the test by 
constructing my own t-stat, the numerator would be just the difference 
in the weighted means - no problem there.  The issue is the standard 
error for the difference in weighted means.  Does anyone know a source 
on this standard error?  Does anyone know of a function (or have one) 
for doing a t-test for weighted data?
Thanks,
Walt
-- 
________________________
Walter R. Paczkowski, Ph.D.
Data Analytics Corp.
44 Hamilton Lane
Plainsboro, NJ 08536
________________________
(V) 609-936-8999
(F) 609-936-3733
[email protected]
www.dataanalyticscorp.com
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