A bank manager wishes to provide prompt service for customers at the bank's drive-up window. The bank currently can serve up to 10 customers per 15-minute period without significant delay. The mean arrival rate is 7 customers per 15-minute period. Let X denote the number of customers arriving per 15-minute period. Assuming X has a Poisson distribution:

a. Find the probability that 10 customers will arrive in a particular 15-minute period. Set up the mathematical model and use the table.
b. Find the probability that 10 or fewer customers will arrive in a particular 15-minute period. Set up the mathematical model and use the table.
c. Find the probability that there will be a significant delay at the drive-up window. That is, find the likelihood that more than 10 customers will arrive during a particular 15-minute period. Set up the mathematical model and use the table.