We provide a very simple formula dubbed EEE that can be applied in any situation of the type described in the question above, is theoretically shown to be justified asymptotically in an enormous variety of situations, and is empirically shown to perform remarkably well in a variety of situations. EEE stands for Elston’s Excellent Estimator and is an equation, to be specified in the method section, which permits simple calculation of power and sample size estimates in many complex situations.
