researchers wish to determine if a new experimental medication will reduce the symptoms of allergy sufferers without the side effect of drowsiness. to investigate this question, the researchers randomly assigned 100 adult volunteers who suffer from allergies to two groups. they gave the new medication to the subjects in one group and an existing medication to the subjects in the other group. forty-four percent of those in the treatment group and 28% of those in the control group reported a significant reduction in their allergy symptoms without any drowsiness. the experimental units are the
