A clinical trial is planned to compare an experimental medication designed to lower blood pressure to a placebo. Before starting the trail, a pilot study is conducted involving 10 participants. The objective of the study is to assess how systolic blood pressure Changes untreated over time. Systolic blood pressures are measured at baseline and again 4 weeks later. Compute a 95% confidence interval for the mean difference in blood pressures over 4 weeks.
Baseline: 120 145 130 150 152 143 126 121 115 135
4 weeks 122 142 1356 158 155 140 130 120 124 130