Med. 6.28 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 antihyper- tensive treatment. Ten hypertensive patients (diastolic blood pressure between 90 and 115 mmHg) were studied after at least 18 months on antihypertensive treatment. SENS readings, which were obtained before and after the patients were placed on an antihypertensive treatment, are given here. Patient 1 2 3 4 5 6 7 8 9 10 Before treatment 22.86 7.74 15.49 9.97 1.44 9.39 11.40 1.86 -6.71 6.42 After treatment 6.11 -4.02 8.04 3.29 -0.77 6.99 10.19 2.09 11.40 10.70 a. Is there significant evidence that the mean SENS value decreased after the patient received antihypertensive treatment? b. Estimate the size of the change in the mean SENS value. c. Do the conditions required for using the t procedures appear to be valid for these data? Justify your answer.6.36 The effect of Benzedrine on the heart rate of dogs (in beats per minute) was examined in an experiment on 14 dogs chosen for the study. Each dog was to serve as its own control, with half of the dogs assigned to receive Benzedrine during the first study period and the other half assigned to receive a placebo (saline solution). All dogs were examined to determine the heart rates after 2 hours on the medication. After 2 weeks in which no medication was given, the regimens for the dogs were switched for the second study period. The dogs previously on Benzedrine were given the placebo, and the others received Benzedrine. Again, heart rates were measured after 2 hours. The following sample data are not arranged in the order in which they were taken but have been summarized by regimen. Use these data to test the research hypothesis that the distribution of heart rates for the dogs when receiving Benzedrine is shifted to the right of that for the same animals when on the placebo. Use a one-tailed Wilcoxon signed-rank test with a - .05. Dog Placebo Benzedrine Dog Placebo Benzedrine 250 258 296 305 271 285 301 319 243 245 10 298 308 JaUAWNH 252 250 11 310 320 266 268 12 286 293 272 278 13 306 305 293 280 14 309 313