There is only one pharmacist dispensing prescribed medicines in a small pharmacy. The pattern of customers arriving to obtain a prescritpion follows a Poisson distribution with a mean of six per hour. The times taken for a pharmacist to dispense the drugs are exponentially distributed with a mean of 7.5 minutes.
a) (i) What is the traffic intensity of the system?
(ii) What is the mean queue length?
(iii) What is the mean waiting time in the queue?