Refer to Question 7. If two additional variables are now added to the model in that question, then
Ŷ = b0 + b1X1 + b2X2 + b3X3
where
X2 = average daily traffic flow, cars
X3 = number of competing filling stations
The empirical results now are

a. Which independent variable seems now to be the most significant predictor?
b. Are X1, X2, and X3 significant at the .05 level?
c. How might you explain why b1 is now larger?
d. Interpret b2.

Variable Variable Regression Coefficient t-Value Variable Mean Range 10,000 10,000 3,000-20,000 b 4.0 1.3 6.000 2,500-12,500 b4.0 1.0 Xa X, 12 0-25 b 21,000 1.0 bo 10,000