A set of sample scores from an experiment has an N = 28 and a mean = 52. H 1 is directional, predicting an effect of the independent variable which decreases the magnitude of the dependent variable. H 0 asserts the sample is a random sample from a population of scores where µ = 55 and s = 12. a = 0.051 tail. Using the z test to analyze the data, the power of the experiment to detect a real effect such that µreal = 53