The following Minitab printout is for a stepwise regression with 10 independent variables and 50 observations:

a. List the order in which the independent variables have been introduced.
b. What is the multiple regression equation after two independent variables have been introduced?
c. As of step 3, three variables have been introduced. Which, if any, partial regression coefficients differ significantly from zero at the 0.05 level? At the 0.02 level?

Stepwise Regression: y versus xl, x2, x3, x4, x5, x6, x7, x8, x9, x10 Alpha-to-Enter 0.05 Alpha-to-Remove: 0.1 Response is on 10 predictors, with N-50 1 y Step 83.91 -0.33 -2.39 0.021 Constant 106.85 124.76 T-Value P-Value -0.35 2.65 0.011 -0.30 -2.30 0.026 -0.33 -2.30 0.026 -0.38 -2.70 0.010 T-Value P-Value x9 T-Value p-Value -0.27 -2.07 0.044 13.8 10.63 8.76 3.9 13.2 19.66 16.25 0.9 12.8 26.52 21.73 -0.9 R-Sq R-Sq(adj) C-p