The probability that equipment used in a hospital lab will need recalibration is given in the following table. A service firm is willing to provide maintenance and provide any necessary calibration for a fee of 3600 per month. Recalibration costs 300 per time. Which approach would be most cost effective, recalibration as needed or the service contract? Number of recalibration Probability of occurrence 0 0.15 1 0.05 2 0.40 3 0.23 4 0.17