The average number of items (such as a drink or dessert) ordered by a Noodles & Company customer in addition to the meal is 1.4. These items are called add-ons. De ne X to be the number of add-ons ordered by a randomly selected customer.
(a) Justify the use of the Poisson model.
(b) What is the probability that a randomly selected customer orders at least 2 add-ons?
(c) No add-ons?
(d) Construct the probability distribution using Excel or Appendix B, make a graph of its PDF, and describe its shape.