Calculate queuetime for incoming calls to callsenter

Can I calculate the average time a calling customer will have to wait on the line until the call is answered, by using the following information;

Average handle time on each call
Number of agents answering
Number of calls that's being offered/are coming in

I would like to make a graphic presentation like the one in the picture below.
This example shows a diagram of the waiting time being reduced as the number of agents increases (don't know why it's so small).
The handle time and the waiting time is expressed in seconds. The language is in norwegian.
Attachment 25602