The pull strength of a wire bond is an important characteristic. The table below gives information on pull strength y, die height x1, post height x2, loop height x3, wire length x4, bond width on the die x5, and bond width on the post x6. [Data from Myers and Montgomery (2002)]

(a) Fit a regression model using all independent variables.

(b) Use stepwise regression with input significance level 0.25 and removal significance level 0.05. Give your final model.

(c) Use all possible regression models and computes R~, Cp, s2, adjusted R~ for all models.

(d) Give final model.

8.0 2.1 19.6 29.6 94.9 5.2 2.3 8.3 8.5 8.8 9.0 9.3 9.3 9.5 9.8 10.0 10.3 6.4 10.5 6.0 10.8 11.0 11.3 11.5 32.4 31.0 32.4 95.6 28.6 18.8 30.6 84.5 32.4 32.6 32.2 93.6 5.2 19.8 89.7 2.1 1.8 5.8 2.0 96.2 2.0 19.6 6.4 5.8 5.2 5.6 6.0 5.2 5.8 19.4 18.6 2.2 2.0 2.1 2.2 2.1 2.3 2.1 2.0 2.1 2.2 2.1 2.1 86.5 1.8 2.1 1.9 19 2.1 18 1.6 20.4 19.0 20.8 88.8 85.7 19.9 31.8 32.6 86.0 87.1 93.1 83.4 94.5 18.0 2.1 2.1 20.6 20.2 20.2 19.2 17.0 33.4 31.8 32.4 31.4 33.2 35.4 34.0 34.2 6.2 6.2 6.2 5.6 1.9 1.8 2.1 83.4 19 2.1 85.2 84.1 86.9 11.8 6.0 19.8 2.0 1.8 1.8 12.3 12.5 5.8 18.8 2.1 18.6 5.6 1.9 2.0 83.0 cicicicieiciciciNNci