Hi, I am doing a study design and planning to do a moderation study. This is the simplest model. However, I am struggling with the calculation of sample size. How do I calculate the sample size for a moderation study (with power of 0.8, error of 0.05, effect size of 0.36)? Can I do this on G*power?

Actually I have seen similar question, and they suggest doing data simulation in R or other software first. I am still confused with the detailed procedure. 

Thanks in advance!

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