Sigmund wrote four checks last month, and these were the only transactions for his checking account . accourding to his register, his balance is 1065.27. if the four checks were for 168.48, 168.93, 177.48, and 177.93, the check for which amount has not yet been cleared

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?