Hello everyone,
I hope you are all doing well.
I have a friend that is designing a study evaluating the proportion of two biomarkers in three different populations of patients.
Population A is the reference
Population B would have a proportion of the two biomarkers (50 % compared to A)
Population C would have a proportion of the two biomarkers (25% compared to A)
I cannot find the way to do this calculation after reading the whole manual of power and sample size of Stata 15.
Thanks in advance for your help.

Donia