I am researching a framework using regression analysis. With the beta coefficients I now want to calculate the correlation between my variables with the influence of another. So I have the beta of 0,465 of the independent on the dependent variable with a sample size of 176; additionally another independent variable has an impact on the relationship with beta 0,733 and the sample size 30. How do I calculate the final impact considering both different sample sizes?
You don't. You have to include both variable in the model in order to do this, and the model has to be on one set of data.