Consider the bearing wear data in Exercise 12-7 with no interaction.
(a) Test for significance of regression using a = 0.05. What is the P-value for this test? What are your conclusions?
(b) Compute the t-statistics for each regression coefficient. 000000Using   0.05, what conclusions can you draw?
(c) Use the extra sum of squares method to investigate the usefulness of adding x2 = load to a model that already contains x1 = oil viscosity. Use a = 0.05.