Answer:
Arrival rate λ= 19 pages per hour
Service rate μ = 20 pages per hour
a. Average utilization rate P = λ/μ
Average utilization rate P = 19/20
Average utilization rate P = 0.95
Average utilization rate P = 95%
b. Probability that more than four pages are waiting or being word processed Pn>4 = 1 - (P0 + P1 + P2 + P3 + P4)
Pn>4 = 1 - (0.05*(1+0.95 + 0.95^2 + 0.95^3 + 0.95^4))
Pn>4 = 1 - (0.05*4.524)
Pn>4 = 1 - 0.2262
Pn>4 = 0.774.
c. Average number of pages waiting to be word processed Lq
Lq = λ²/μ(μ-λ)
Lq = 19²/20(20-19)
Lq = 361/20
Lq = 18.05