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st: standard deviation for the difference in means
From
Michael McCulloch <[email protected]>
To
Statalist Statalist <[email protected]>
Subject
st: standard deviation for the difference in means
Date
Sun, 6 Jun 2010 12:57:51 -0700
Apologies for a basic statistics question:
I wish to estimate sample size for an experiment in which, from
previously published data, I have available the following summary
measures (but not the raw data):
Group A:
mean of a continuous variable
standard deviation of that continuous variable
sample size
Group B:
mean of the same continuous variable
standard deviation of that continuous variable
sample size
And, the P value based on two-sample t tests comparing differences in
between-group means.
My question is, with those values (and none other) available, is it
possible to estimate the standard deviation for the difference in
between-group means.
Best wishes,
Michael McCulloch, LAc MPH PhD
Pine Street Foundation
124 Pine Street
San Anselmo, CA 94960-2674
tel: 415-407-1357
fax: 206-338-2391
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