=+14. An additive model for the Gas prices is:

Dependent variable is: Gas R squared = 28.6% R squared (adjusted) = 3.3%

s = 0.5524 with 47 - 13 = 34 degrees of freedom Variable Coefficient SE(Coeff) t-ratio P-value Intercept 66.3101 146.9 0.451 0.6546 Time -0.031816 0.0732 -0.435 0.6664 Jan -0.036401 0.3907 -0.093 0.9263 Feb 0.162901 0.3907 0.417 0.6793 Mar 0.395053 0.3908 1.01 0.3192 Apr 0.644704 0.3910 1.65 0.1084 May 0.788105 0.3914 2.01 0.0520 Jun 0.774757 0.3918 1.98 0.0562 Jul 0.673908 0.3923 1.72 0.0949 Variable Coefficient SE(Coeff) t-ratio P-value Aug 0.544059 0.3929 1.38 0.1752 Sep 0.333961 0.3937 0.848 0.4022 Oct 0.167112 0.3945 0.424 0.6745 Nov -0.029645 0.4226 -0.070 0.9445