2. A new medication claims to reduce the average blood pressure of patients. A random sample of 10 patients is selected and their blood pressure measurements before and after taking the medication are shown in Table 4 (in mm Hg). Table 4 Patient Before Medication After Medication 1 140 138 2 145 142 3 150 149 4 138 140 5 142 143 6 155 157 7 130 128 8 148 146 9 152 10 137 155 139 Test whether the medication is effective in reducing blood pressure at a significance level of 0.05 using the one-sample sign test. (Total / Jumlah: 20 )