Problem 8.47 Refer to the lead absorption data set of Problem 1.18. Construct a Q–Q plot to assess, informally, the plausibility of the normality hypothesis for the data in the first column (the exposed group). Comment on whether or not the points (zj , x(j)) appear to lie along a straight line.

(b) Test the data for normality by applying the Shapiro–Wilk test. State the alternatives, decision rule,and conclusion.