Homework 8 1. Portions of the SAS output for several regression models are given below. The response variable is body fat (Y), and predictor variables are triceps skinfold thickness (X1), thigh circumference (X2) and midarm circumference (X3), see p.179 of textbook . Parameter Standard Variable Estimate Error t Value Pr > Itl Model 1 Intercept 117 . 08469 99. 78240 1. 17 0. 2578 X1 4. 33409 3. 01551 1. 44 0. 1699 X2 -2.85685 2. 58202 -1. 11 0. 2849 X3 -2. 18606 1. 59550 -1.37 0. 1896 Model 2 Intercept -1. 49610 3.31923 -0. 45 0. 6576 X1 0. 85719 0. 12878 6. 66 <. model intercept x2 x3 x1 a medical investigator asks the following questions. how would you answer in is not significant however .0001 which result should i believe or p-value for smaller than does this mean more important predictor has negative slope positive y increase decrease with think have because thigh circumference tends to body weight. so prefer r2="0.7781" even if higher do agree when added regression of versus mse became expected but standard error actually bigger. explain>