Compute the sample size required for a hierarchical multiple regression study. The calculator computes the minimum required sample size for a significance test of the addition of a set of predictor variables B to the model, over and above another set of predictor variables A, given the expected effect size, probability level, and power level. Knowing the correct sample size is very useful for ensuring that hierarchical regression-based analytics studies have enough power to detect the expected effect.Please provide the necessary values, and then click 'Calculate'.