Accounting question! please help!

4. what inspired selfridge to ensure that customers in his store could browse at their leisure?

During winter, red foxes hunt small rodents by jumping into thick snow cover. researchers report that a hunting trip lasts on average 19 minutes and involves on average 7 jumps. they also reported that, surprisingly, 79% of all successful jumps are made in the northeast direction. three variables are mentioned in this report. the third variable mentioned is

An experimenter studies the relationship between caffeine and reaction time. she designs her experiment with four groups. group 1 receives 100 mg of caffeine each in their cups of coffee, group 2 receives 200 mg of caffeine each in their cups of coffee, group 3 receives 300 mg of caffeine each in their cups of coffee, and group 4 receives no coffee. twenty minutes later, participants from all the groups are given a reaction-time test. in this experiment, which group is the control group?