Drivers who come to get their licenses at the Department of Motor Vehicles have their photograph taken by an automated machine that develops the photograph onto the license card and laminates the complete license. The machine requires a constant time of 4.5 minutes to prepare a completed license. If drivers arrive at the machine at a mean rate of 10 per hour (Poisson distributed), determine the average length of the waiting line and the average waiting time in the line.

I just need to know HOW TO CALCULATE (L) & (W) >>>> The answer for (L) is 1.877 (1.88) and the answer for (W) is 0.19 so please do not give a calculation that does not equal 1.88 or 0.19

Thanks!