A small town with one hospital has $3$ ambulances to supply ambulance service. Requests for ambulances during nonholiday weekends average $0\mathrm{.}58$ per hour and tend to be Poisson$-$distributed. Travel and assistance time averages $1\mathrm{.}90$ hours per call and follows an exponential distribution Use Table $18\mathrm{.}4$ a$.$ Find system utilization. $($Round your answer to the nearest whole percent$)$ System utilization b$.$ Find the average number of customers waiting. $($Round your onswer to $3$ decimal places.$)$ Average number of customers Find the average time customers wait for an ambulance. $($Round your answer to $3$ decimal places.$)$