9. The paper \"Effect of long-term blood pressure control on salt sensitivity\" [Journal of Medicine (1997) 28: 147-156] describes a study evaluating salt sensitivity (SENS) after a period of antihypertensive treatment. Ten hypertensive patients (diastolic blood pressure between 90 and 1 15 mmHg) were studied after at least 18 months on antihypertensive treatment. SENS reading, which were obtained before and after the patients were placed on an antihypertensive treatment, are given here: Data for - roblem 9 22.86 a. Is there significant evidence that the mean SENS value decreased after the patient received hypertensive treatment? b. Estimate the size of the change in the mean SENS value. c. Do the conditions required for using the tprocedures appear to be valid for these data? Justify your