20. A criminologist was interested in whether there was any disparity in sentencing based on the race of the defendant. She selected at random 18 burglary convictions and compared the prison terms given to the 10 white defendants and 8 black defendants sampled. The sentence lengths (in years) are shown for the white and black offenders. Using these data, test the null hypothesis that whites and blacks convicted of burglary in this jurisdiction do not differ with respect to prison sentence length. Whites Blacks NWAQUANALW AMALIW - 21. In a field experiment on the effects of perceived control on feelings of well-being, residents on one floor of a nursing home were given opportunities for increased control in their lives (for example, arrange their own furniture, decide how to spend free time, choose and take care of a plant), whereas the residents on another floor were treated as usual. That is, the staff took care of these details. The feelings of well-being (on a 20-point scale) follow for the conditions of increased and no increased control. Using these data, test the null hypothesis that this minimal manipulation of perception of control had no effect on the residents' feelings of well-being. Increased Control No Increased Control 15 17 14 11 13