DrWalters Finds That Students Who Work Less Than 10 Hours

Multiple Choice

Dr.Walters finds that students who work less than 10 hours a week have significantly higher test scores than students who work more than 10 hours a week.In order to determine the magnitude of the effect of work hours on test scores,she should calculate a(n)

A) critical value.
B) effect size.
C) null calculation.
D) degree of freedom.