Suppose your company runs a shuttle business of a hotel to and from the local airport. The costs for different customer loads are: 1 customer: $30 2 customers: $32 3 customers: $35 4 customers: $38 5 customers: $42 6 customers: $48 7 customers: $57 8 customers: $68. If you are compensated $10 per ride, what customer load would you choose?