The average number of item (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. Define 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