A doctor wants to know if a blood pressure medication is effective. Six subjects have their blood pressures recorded. After twelve weeks on the medication, the same six subjects have their blood pressure recorded again. For this test, only systolic pressure is of concern. Test at the 1% significance level. (Calculate \"after\" "before.") Patient A B C D E F Before 161 162 165 162 166 171 After 158 159 166 160 167 170 What is the test statistic? (If using the 2 distribution round your answer to two decimal places, and if using the t distribution round your answer to three decimal places.) _ -4154 x Which formula should be used to calculate he test statistic