Four different coatings were evaluated for corrosion protection of metal pipe buried in soil. The experiment was designed in the following way: Twelve sections of the same type of pipe were randomly selected. The sections of pipe were randomly assigned to three different soil types with four sections assigned to each type. . Within each soil type, the four coatings were randomly assigned to the four sections with each section receiving only one coating. Each section was buried for the same amount of time. The corrosion amounts appear in the following table. Soil 1 70 53 47 51 Coating A Coating B Coating C Coating D Soil 2 55 51 45 43 Soil 3 56 48 50 52 (a) Should coating or soil be used for blocking? Why? (b) Construct an ANOVA table by hand. (c) Do you have enough evidence to conclude that there are differences among the four coatings with respect to the mean corrosion amount for all sections of pipe? Justify your answer using a = 0.05 and assuming all necessary conditions hold.