Refer to Exercise 16.21. a. Test at the = .05 level if there is a significant

Refer to Exercise 16.21.
a. Test at the α = .05 level if there is a significant difference in the mean thicknesses of the coating from the three processes without taking into account the temperature in the lab.
b. Are your conclusions from part (a) consistent with your conclusions from Exercise 16.21? Explain your answer.