c number of servers = 1
λ arrival rate = 98 customers per hour for 2 servers i.e. 49 customers
µ serving rate = 55 customers per server per hour
ρ = λ/(cµ) = (98 ÷ 2)/ 55 = 0.8909
γ =λ µ = 0.8909 (= ρ in case of c = 1)
Overall system utilization = ρ = 89.09 %
The probability that all servers are idle (Po) = 0.1091
Average number of customers in the queue (Lq) = ( ) ( )2 0
! 1
P
c
c
×
− ρ
γ ρ
= 7.2758
Average time customer spends in the queue (Wq) = Lq/λ = 0.1485 hours