CPU$-$on$-$Demand $($CPUD$)$ is 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 $4$ hours. Executing each job takes, on average, $2$ hours on the supercomputer and the standard deviation of the processing time is $4\mathrm{.}4$ 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$)?$ Note: Do not round intermediate calculations. Round your answer to $1$ decimal place.