21. A nutritionist IS investigating the effects of a rigorous walking program on systolic blood pressure (SBP) in patients with mild hypertension. Subjects who agree to participate have their systolic blood pressure measured at the start of the study and then after completing the 6-week walking program. The data are

Subject Starting SBP Ending SBP

1 140 128

2 130 125

3 150 140

4 160 162

5 135 137

6 128 130

7 142 135

8 151 140

Based on the data, is there evidence that SBP is significantly reduced by the walking program? Run the appropriate test at the 5% level of significance