A study was conducted to determine whether relaxation training, aided by biofeedback and meditation, could help in reducing high blood pressure. Subjects were randomly allocated to a biofeedback group or a control group. The biofeedback group received training for 8 weeks. The table reports the reduction in systolic blood pressure (mm Hg) after eight weeks.42
(a) Construct a 95% confidence interval for the difference in mean response.
(b) Interpret the confidence interval from part (a) in the context of this setting.