Estimate Group Means for Significance

[mekono]

Hi,

For a project, I have confirmed the sample size, but am wanting to know what is the average difference that’s needed across the two groups to be considered significantly different. Any idea on where to start with this? I have 618 in each cohort , looking for power at 0.80 and alpha of 0.05

[PaigeMiller]

You also need to estimate (or guess at) the root mean square error or standard error of the mean. Then you can use PROC GLMPOWER to determine the size of mean difference that will be statistically significant.