Serious environmental problems arise from absorption into soil of metals that escape into the air from different industrial operations. To ascertain if absorption rates differ among soil types, six soil sampleswere randomly selected from fields having five different soil types (A, B, C, D, and E) in an area known to have relatively uniformexposure to themetals studied. The 30 soil sampleswere analyzed for cadmium (Cd) and lead (Pb) content. The results are given in Table 6.37. Perform separate analyses to determine whether there are differences in cadmium and lead content among the soils. Assume that the cadmium and lead content of a soil directly affects the cadmium and lead content of a food crop. Do the results of this study lead to any recommendations?

Check the assumptions for both variables. Does this analysis affect the results in the preceding? If any of the assumptions are violated, suggest an alternative analysis.

6.10 Chapter Exercises 317 Table 6.37 Data for Exercise 11 Soil A B C D E Cd Pb Cd Pb Cd Pb Cd Pb Cd Pb 0.54 15 0.56 13 0.39 13 0.26 15 0.32 12 0.63 19 0.56 11 0.28 13 0.13 15 0.33 14 0.73 18 0.52 12 0.29 12 0.19 16 0.34 13 0.58 16 0.41 14 0.32 13 0.28 20 0.34 15 0.66 19 0.50 12 0.30 13 0.10 15 0.36 14 0.70 17 0.60 14 0.27 14 0.20 18 0.32 14 LO.1