cpu-on-demand (cpud) offers real-time high-performance computing services. cpud owns 5 supercomputers that can be accessed through the internet. their customers send jobs that arrive on average every 4 minutes. the standard deviation of the interarrival times is 4 minutes. executing each job takes on average 16 minutes on one of the supercomputers (during this time, the computer cannot perform any other work). the standard deviation of this processing time is 24 minutes. how long does a computer have to wait to have a job completed