Statistic Question

Mike’s Pizza has a 20-minute guarantee that states “If your order is not delivered within 20
minutes of your order being taken, then your order will be free.” Mike believes that he has a
success rate of 95%. Records are kept for every order taken. A random sample of of n=200
orders is collected and it is determined that 17 people did not receive their order within the
20-minute guarantee period.
a. If Mike’s claim were correct, what is the probability of observing 17 or more people
not receiving their order within the 20-minute guarantee period?
b. Based on your findings in part (a), is there any evidence to suggest Mike’s claim is
inaccurate?