Answer:
0.8
Step-by-step explanation:
The Utilization factor p ;
p = mean service rate (λ) / mean arrival rate (μ)
The mean arrival rate : 5 minutes apart
Mean service rate = 4 minutes
Hence, mean arrival rate λ per hour = 60 / 5 = 12 persons per hour
Mean service rate μ per hour = 60 / 4 = 15
Utilization factor p = (mean arrival rate / mean service rate)
p = 12 / 15
p = 0.8