4) Suppose you want to extend Model 1 to have a quadratic model, such as: Models5: Y=b0+b1X,+b2 X; +e, Find the marginal effect of the annual income on the health insurance premium. Suppose a person earns a $50,000 yearly wage and salary. What is the marginal effect of the health insurance premium if he/she has $10000 extra income? reg phipval incp_wag Source SS df MS Number of obs = 1, 000 F (1, 998) = 1. 27 Model 13913070.8 1 13913070.8 Prob > F 0. 2592 Residual 1. 0897e+10 998 10918610.4 R-squared 0 . 0013 Adj R-squared = 0 . 0003 Total 1 . 0911e+10 999 10921607.9 Root MSE 3304.3 phipval Coefficient Std. err. t P> | t| [95% conf. interval] incp_wag . 0019393 . 001718 1 . 13 0 . 259 -. 001432 . 0053105 _cons 2489 . 509 139. 137 17.89 0 . 000 2216. 475 2762 . 544