On Mar 2, 2012, at 7:05 PM, Duncan Murdoch wrote:
On 12-03-02 4:47 PM, Jun Shen wrote:
Dear list,
If I know the standard error for k1 and k2, is there anything I can
call in
R to calculate the standard error of k1/k2? Thanks.
No, because it depends on the joint distribution of k1 and k2. Even
if you knew they were independent, that would not be sufficient
(though you could use the delta method to get an approximation in
that case; look it up).
A nice article with useful information on three approaches to this
problem appeared in BMC Medical Research Methodoogy:
"Methods for confidence interval estimation of a ratio parameter with
application to location quotients", by Beyene and Moineddin.
http://www.biomedcentral.com/1471-2288/5/32
Both were at Department of Public Health Science, University of
Toronto, Toronto, Ontario, Canada, when this appeared in 2005. I
thought they might have been neighbors of yours, Duncan, but I looked
at a map and see that my understanding of Ontario geography is not
particularly accurate.
Duncan Murdoch
Jun
--
David Winsemius, MD
West Hartford, CT
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