sample size determination - comparing means for different size samples
Hello, At an R prompt, type ?power.t.test Hope this helps, Rui Barradas Em 06-06-2013 20:58, Rebecca Greenblatt escreveu:
Looking to determine sample sizes for both my experimental and control groups (I want only a small portion of my participants in my experimental condition) in order to compare population means. I would be able to estimate standard deviation beforehand. I'm using the bpower function from the Hmisc R package, specifically bsamsize to compare population proportions, but was wondering if there was an equivalent function for comparing means.