A hotel has designed a new system for room service delivery of breakfast that allows the customer to select a specific delivery time. The file Satisfaction contains the difference between the actual and requested delivery times (a negative time means that the breakfast was delivered before the requested time) recorded for 30 deliveries on a particular day along with whether the customer had previously stayed at the hotel.

a. Using all the data as the training sample, develop a classification tree model to predict the probability that the customer will be satisfied based on the delivery time difference and whether the customer had previously stayed at the hotel.

b. What conclusions can you reach about the probability that the customer will be satisfied?