A hand sanitizer was advertised to be more effective at killing bacteria than any antibacterial soap. Students were split evenly into 4 groups to test this claim. Groups 1-3 washed their hands using the assigned hand sanitizer or soap (see table) and warm water for two minutes, and then dried their hands with a paper towel. Group 4 rubbed their hands vigorously for 2 minutes in warm water, without any soap or sanitizer, and then dried their hands with a paper towel. After washing, each student’s hands were swabbed and the swab was applied to a culture plate and incubated. Finally, the bacterial cultures were counted. What are the independent and dependent variables in this experiment? What is the control group? List 3 constants. *