Problem
CPU-on-Demand (CPUD) offers real-time high-performance computing services. CPUD owns 1 supercomputer that can be accessed through the Internet. Their customers send jobs that arrive, on average, every 3 hours. The standard deviation of the inter-arrival times is 4 hours. Executing each job takes, on average, 2 hours on the supercomputer and the standard deviation of the processing time is 4.4 hours.
On average, how long will it take to complete a job (from the time it is submitted by the customer until the time it is completed)?