Question

1. 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 7 participants. The objective of the study is to assess how systolic blood pressure changes over time untreated. Systolic blood pressures are measured at baseline and again 4 weeks later. Is there a statistically significant difference in blood pressures over time? Run the test at a 5% level of significance.

Baseline           120      145      130      160      152      143      126     

4 Weeks           122      142      135      158      155      140      130     

            Difference        -2         3          -5         2          -3         3          -4         S Differences = -6

            Difference²      4          9          25        4          9          9          16        S Differences² = 76

Xd=-0.86 sd=3.44

Step 1.           Set up hypotheses and determine level of significance

Step 2.            Select the appropriate test statistic

                                

Step 3.            Set up decision rule

                       

Step 4.            Compute the test statistic

           

Step 5.            Conclusion

Answer 1