Medicine and Clinical Studies Calcium blockers have many effects on a person's heart rate. They are most often used to slow the heart rate in patients with atrial fibrillation. This class of medications work to decrease the heart pumping strength and, therefore, ease tension in blood vessels.9 Suppose an experiment was conducted to determine whether calcium blockers affect heart rhythms in patients with arrhythmias. A random sample of patients was obtained, and their resting pulse rate was measured (in beats per minute). After a two-week regimen of a calcium blocker, each person's resting pulse rate was measured again. Suppose no assumptions can be made about the shape of the continuous distributions of before and after pulse rates.
a. Conduct a sign test to determine whether there is any evidence that the median pulse rate before the calcium blocker medication is different from the median pulse rate after the medication. Use a significance level of a = 0.01.
b. Do you believe the assumptions for the sign test are valid in this case? Why or why not?