A researcher is interested in whether trouble-making among inmates differs by whether or not inmates have psychopathology. A group of inmates in a certain pod at a state correctional facility were rank-ordered on the basis of how much trouble they caused while in confinement. They are divided into two groups based on their scores on the Holden SS (a test of psychopathology): low and high. Is there a difference in rankings of trouble-making by psychopathology group? ___________ is the dependent variable in this problem. ___________ is the independent variable in this problem. ___________ is the appropriate statistical test to use for this