12- Beta is the probability of: A) Rejecting the null when it is true B) Rejecting the null hypothesis when it is in fact false C) Not rejecting the null hypothesis when it is in fact false D) Not rejecting the research hypothesis when it is false 13- The effect size is one of two major factors that contribute to power: the other factor is: A) sample size B) the minimum meaningful difference C) the sample's standard deviation D) the mean of the known population 14- The significance level is equal to the chance of making a: A) Type Il error B) Type l error 15- Effect size decreases when there is: A) A smaller difference between the two population means B) A greater difference between the two population means