A study is done to determine the effects of removing a renal blockage in patients whose renal function is impaired because of advanced metatstatic malignancy of nonurologic cause. The arterial blood pressure of a random sample of 10 patients is measured before and after surgery for treatment of the blockage yielded the following data: Patient ID Before After 1 140 90 111 80 2 122 120 4 105 100 5 150 123 160 144 111 84 98 94 90 90 10 102 104 Please conduct a sign test to find out whether the surgery changed the arterial blood pressure. 67 8.