b. The second model has better overall explanatory power, but a better R2 is only gained at the expense of other factors. The first model is better at explaining individual coefficient estimates than the second. c. The second model is unambiguously better; since R2 signifies the explanatory power of the entire model, the second model's other results (expected signs, t-stats/p-values) are not as important. The first model should be seen as inferior. d. The independent variables in the first model are not statistically significant, despite what the t- stats and p-values suggest. Question 15 If you ran a regression using data on many different used car sales, and had selling price as the dependent variable, the expected sign on the variable "mileage" (how many miles the car had been driven) would be negative. Select one: True False Question 16 Question text If you ran a regression using data on many different used car sales, and had selling price as the dependent variable, the expected sign on the variable "sound" (a dummy variable representing whether the car has upgraded speakers, 1 = upgraded and 0 = standard) would be negative. Select one: True False The following are regression results where Car Price is the dependent variable: Regression Statistics R2=0.446 Adjusted R2=0.441 Observations = 804 Independent Variables Coefficients Standard Error t Stat P-value