Blood Pressure 1

Determine whether a medication was successful in reducing blood pressure.
Problem

To observe the effectiveness of a medication in reducing blood pressure, an experiment was conducted in which researchers collected data from a random sample of individuals who were considered to have high blood pressure. The diastolic blood pressure of these individuals was recorded, after which they were placed on the medication. One month later, their diastolic pressure was recorded again.
Determine whether the data gives good evidence that the medication was effective in reducing blood pressure by carrying out a test of significance (at level ? = 0.05), pairing the two blood pressure recordings for each subject.