This question already has an answer here:
- Combining two covariance matrices 1 answer
I have the mean & SD of several different time points, I want to combine them into one mean and SD. Is it possible? Example;
At 1 hour; mean=5, SD=1, n=42
At 2 hours; mean=6, SD=3, n=42 and so on.
Any equation to do that?
Note: at some time points, I have different group numbers (n), due to missing one or two patients. I really appreciate your help, thanks!