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 $5$ hours. The standard deviation of the interarrival times is $5$ hours. Executing each job takes on average $7$ hours on the supercomputer and the standard deviation of the processing time is $3$ hours.how long does the customer have to wait to have the job completed?