Chapter 15.4, Problem 15E

Eight subjects were asked to perform a simple puzzle-assembly task under customary conditions and under conditions of stress. During the stressful condition, the subjects were told that a mild shock would be delivered 3 minutes after the start of the experiment and every 30 seconds thereafter until the task was completed. Blood pressure readings were taken under both conditions. Data in the accompanying table represent the highest reading during the experiment.

Do the data present sufficient evidence to indicate higher–blood pressure readings during conditions of stress? Analyze the data by using the Wilcoxon signed-rank test for a matched-pairs experiment. Give the appropriate p-value.