Final answer:
The provided question lacks specific data on delivery times; therefore, an accurate answer cannot be given based on the information provided.
Step-by-step explanation:
The question provided does not include enough specific data to determine the longest delivery time in minutes from the options given (15, 20, 25, 30). However, if we relate this to the information that is available, we can deduce that since one customer is expected every two minutes, a sample size of 50 restaurants would likely change the confidence interval estimate for the mean delivery time, as shown in the Try It exercise.
Similarly, with the information that it takes six minutes on average for three customers to arrive, we can infer a steady rate of customer arrivals, but without explicit data on delivery times or a distribution showing the frequency of each delivery time, the question on the largest number of deliveries taking a specific number of minutes cannot be accurately answered.