I want to run a multivariate regression data analysis. I have 5 predictors--two of them are binary--and one DV.
When planning to use Multivariate Regression with some binary categorical predictors, how do I find the sample size I need to justify this test using G* Power?
Is it any different than having all continuous predictors?
I know how to do it when I have predictors that are all continuous. The procedure I use: F tests -> Linear multiple regression: Fixed model -> Rsquare deviation from zero with .15 effect size and .05 err probability. When I execute/calculate this, I get a total sample size of 138.
I'm going to have to explain this to my committee for my thesis proposal soon.