Transient points of an electronic inverter are influenced by many factors. Table below gives data on the transient point (y, in volts) of PMOS-NMOS inverters and five candidate regressors:x1 = width of the NMOS device, x2 = length of the NMOS device, x3 = width of the PMOS device, x4 = length of the PMOS device, and Xs = temperature ("C). Observation Number X1 X2 X3 X4 XS Y 12 8 3 3 3 25 0.293 13 3 6 3 3 50 2.252 1 3 3 3 3 0 0.787 14 3 8 8 3 50 9.167 N 8 30 8 8 0 0.293 15 4 4 8 50 0.694 3 3 61 6 6 0 1710 16 5 2 2 2 50 0.379 4 4 12 0 0.203 17 2 2 2 3 50 0.485 8 7 6 5 0 0806 18 10 15 3 3 50 3.345 15 6 2 3 50 0.208 10 20 5 5 0 4713 19 20 15 6 2 3 75 0.201 8 6 3 3 25 0.607 21 10 4 3 3 75 0.329 CO 6 24 4 4 25 9.107 22 3 8 2 2 75 4.966 9 4 12 14 25 9.210 23 6 6 4 75 1362 10 16 12 8 4 25 1 365 24 2 3 8 6 75 1515 3 25 4.554 25 3 8 8 75 0.751 11 3 10 8 8 Round your answers to 2 decimal places (e.g. 98.76). (a) Fit a multiple linear regression model that uses all regressors to these data. Test for significance of regression using a = 0.05. 1x2 + 1 -- The regression model significant at a = 0.05. (b) Test the contribution of each variable to the model using the t-test with a # 0.05. What are your conclusions? significant, B2 v significant, B3 significant. B. significant, and Bs significant at a = 0.05. (c) Delete xs from the model. Test the new model for significance of regression at or = 0.05. Also test the relative contribution of each regressor to the new model with the t-test. Using a = 0.05. what are your conclusions