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 interarrival times is $7$ hours. Executing each job takes, on average, $2$ hours on the supercomputer and the standard deviation of the processing time is $5\mathrm{.}0$ 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$)?$

Note: Do not round intermediate calculations. Round your answer to $1$ decimal place.