Consider a single-server queueing system. It has been observed that (1) this server seems to speed up as the number of customers in the system increases and (2) the pattern of acceleration seems to fit the state-dependent model presented at the end of Sec.

17.6. Furthermore, it is estimated that the expected service time is 8 minutes when there is only 1 customer in the system. Determine the pressure coefficient c for this model for the following cases:

(a) The expected service time is estimated to be 4 minutes when there are 4 customers in the system.

(b) The expected service time is estimated to be 5 minutes when there are 4 customers in the system.