$26.$Cancer Treatment. A hospital provides intravenous $($IV$)$ treatment for cancer patients. To complete treatment of a cancer patient, nurses often need to retrieve medication from the hospital$$s internal pharmacy. Nurses arrive at the internal pharmacy at a rate of four per hour. The pharmacist spends an average of six minutes with each nurse to prepare and dispense the medication. LO $4,5$a$.$Currently, the hospital has one pharmacist. On average, each nurse waits four minutes before the pharmacist is available to confer with the nurse and prepare the corres$-$ponding medication. Find Lq$,$ W$,$ and L for this single$-$server pharmacist operation.b$.$A trial period with a second pharmacist showed that, on average, each nurse waited only one minute before a pharmacist was available. Find Lq$,$ W$,$ and L for this two$-$server pharmacy operation.c$.$If the cost of each nurse is $$30$ per hour and the cost of each pharmacist is $$60$ per hour, is the one$-$server or the two$-$server system more economical?