Question: A clinical trial is planned to compare an experimental medication designed to lower blood pressure to a placebo. Before starting the trial, a pilot study is conducted involving ten participants. The objective of the study is to assess how systolic blood pressure changes untreated over time. Systolic blood pressure are measure at baseline and again 4 weeks later. Compute a 95% confidence interval for the mean difference in blood pressure over 4 weeks.
Baseline: 120, 145, 130, 160, 152, 143, 126, 121, 115, 135
4 weeks: 122, 142, 135, 158, 155, 140, 130, 120, 124, 130