A vehicle oil change company is seeking a new site for its service center. The fixed cost and variable cost per vehicle has been estimated as follows: Site 1: Fixed cost of $6500 per month and variable cost of $3 per vehicle Site 2: Fixed cost of $3500 per month and variable cost of $5 per vehicle Site 3: Fixed cost of $4000 per month and variable cost of $4 per vehicle Site 4: Fixed cost of $5000 per month and variable cost of $6 per vehicle If the number of vehicles estimated to be serviced is 800 per month, and the average service charge per vehicle is $50, where should the new service center be located?