[R] Sample size with ANCOVA

Marc Schwartz marc_schwartz at me.com
Sat Nov 20 15:40:30 CET 2010

On Nov 20, 2010, at 8:31 AM, XINLI LI wrote:

> Dear R users:
>          How to calculate the sample size with ANCOVA? For example, in a
> clinical trial, the correlation between the baseline and one-year follow-up
> blood pressure is 0.7, with a standrad devision 15, in order to detect a 10
> difference between baseline and follow-up with a power = 0.9, and alpha =
> 0.05? Then, how to calculate the sample size with the correlation of 0.7
> between baseline and follow-up?
>    Thanks and regards,
>     Xing

See this post from this past July:



Marc Schwartz

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