Hi All,
I want to know the STATA command to calculate sample size using sample error formula. n=[(z_(α∕2) )σ/SE]^2
I have (SE, CI, SD in the following example) :
What sample size is needed to be 95% confident the mean is within ± 10? The standard deviation is 30.
Thanks.!

I used -power- command but it requires reference mean value while the above formula doesn't require one.
Regards,