Name one other variable that is not included in the data set

Name one other variable that is not included in the data set that you think would be useful as an additional independent variable. Then state whether you think that the additional regressor would have a positive or a negative impact on the maintenance cost and explain your answer.

Maintenance cost per month (in Gasoline Dumimy (J: Diesel, 1 = 3 Dollars Age (in years) Miles per month

Solution

The other variable we can added to the regression is number of passengers(Capacity).