Philippine Airlines (PAL) offers four flights per weekday from MNL (Manila) to Tokyo-Narita (NRT). If adding a fifth flight per weekday would cost USD 15,000.00 per flight, or USD 110.00 per available seat, calculate the incremental costs borne by PAL following a decision to go ahead with a fifth flight per day for a minimal 60-flight trial period. What is the marginal cost? In this case, is incremental cost or marginal cost relevant for decision-making purposes? Explain.