Gubser Welding, Inc., operates a welding service for construction and automotive repair jobs. Assume that the arrival of jobs at the company's office can be described by a Poisson probability distribution with an arrival rate of three jobs per 8-hour day. The time required to complete the jobs follows a normal probability distribution, with a mean time of 1.9 hours and a standard deviation of 1 hour. Answer the following questions, assuming that Gubser uses one welder to complete all jobs:
What is the average number of jobs waiting for service? If required, round your answer to three decimal places.
What is the average time a job waits before the welder can begin working on it? If required, round your answer to one decimal place.
What percentage of the time is Gubser's welder busy?