Statistical hypothesis testing involves testing the: Onull hypothesis. research hypothesis. O significance level. probability level.X found a correlation coefficient of -.707 between hours of exercise each week and a standard measure of body mass. He interprets this as a: strong, positive correlation between hours of strenuous exercise and body mass. weak, positive correlation between hours of strenuous exercise and body mass. weak, negative correlation between hours of strenuous exercise and body mass. O strong, negative correlation between hours of strenuous exercise and body mass