27. In Chapter 14, Problem 18, p. 388, an experiment was conducted to evaluate the effect of decreases in frontalis muscle tension on headaches.

The number of headaches experienced in a 2-week baseline period was recorded in nine subjects who had been experiencing tension headaches. Then the subjects were trained to lower frontalis muscle tension using biofeedback, after which the number of headaches in another 2-week period was again recorded. The data are again shown here.

In that problem, the sampling distribution of D was assumed to be normally distributed, and the analysis was conducted using the t test. For this problem assume the t test cannot be used because of an extreme violation of its normality assumption.
Use the Wilcoxon signed ranks test to analyze the data. What do you conclude, using 0.052 tail?
clinical, health

No. of Headaches Subject No. Baseline After training 23 1 2 17 13 37 3 62 4 10 567 88 9 53 56 10 2 81 60 72