Hi everyone,

I need to convert standard error (SE) into standard deviation (SD). The formula for that is

SE times the square root of the sample size

By 'sample size', does it mean the total sample size or sample sizes of individual groups? For example, the intervention group has 40 participants while the control group has 39 (so the total sample size is 79) So, when calculating SD for the intervention group, do I use 40 as the sample size or 79?

Thank you!

Similar questions and discussions