Question

1. A technician services mailing machines at companies in the Phoenix area. Depending on the type of malfunction, the service call can take 1, 2, 3, or 4 hours. The different types of malfunctions occur at about the same frequency a) Develop a probability distribution for the duration of a service call. b) Draw a graph of the probability distribution c Show that your probability distribution satisfies the conditions required for a discrete probability function. d) What is the probability a service call will take three hours? e) A service call has just come in, but the type of malfunction is unknown. It is 3:00 P.M. and service technicians usually get off at 5:00 P.M. What is the probability the service technician will have to work overtime to fix the machine today? 2. A volunteer ambulance service handles 0 to 5 service calls on any given day. The probability distribution for the number of service calls is as follows Number of Service Calls Probability Number of Probability Service Calls 0 0.10 0.15 0.30 3 0.20 0.15 0. 2 10 a) What is the expected number of service calls? b) What is the variance in the number of service calls? What is the standard deviation?

Answer 1