$7.$ CPU$-$on$-$Demand $($CPUD$)$ offers real$-$time high$-$performance computing services. CPUD owns one supercomputer that can be accessed through the Internet. Its customers send jobs that arrive, on average, every $5$ hours. The standard deviation of the interarrival times is $5$ hours. Executing each job takes, on average, $3$ hours on the supercomputer and the standard deviation of the processing time is $4\mathrm{.}5$ hours.

a$.$ What is the utilization $($as a percent$)$ of CPUD$$s supercomputer?

$8.$ Using the information in the previous question, how long does a customer have to wait to have a job completed?