Chapter 14 Practice Questions Answers

 

14.148 ANSWER:

                (a)                Po = 0.50

                (b)                r = 0.50

                (c)                L = 1

                (d)                Lq = 0.50

                (e)                W = 0.0667 hours

                (f)                Wq = 0.0333 hours

 

14.151 ANSWER:

 

                (a)                Po = 0.5

                (b)                r = 0.5

                (c)                L = 1

                (d)                Lq = 0.5

                (e)                Wq = 0.05 hours

                (f)                W = 0.1 hours

 

14.153 ANSWER:

 

                (a)                r = 0.500

                (b)                Wq = 0.25 time units (minutes)

                (c)                Lq = 0.500

 

14.159 ANSWER:

                (a)                Po = 0.167

                (b)                r = 0.833

                (c)                L = 5

                (d)                Lq = 4.167

                (e)                W = 0.2 hours = 12 minutes

                (f)                Wq = 0.167 hours = 10 minutes

 

14.162 ANSWER:

 

                (a)                r = 0.833

                (b)                Wq = 0.833 hours = 50 minutes

                (c)                P(more than three students waiting) = P(more than four students in system) = 0.402

                (d)                P(someone will have to stand) = P(more than five students in system) = 0.335

 

14.163 ANSWER:

 

                (a)                0.8

                (b)                3.2

                (c)                The average time waiting is 0.33 hours (or 20 minutes) so this will likely be a problem.

 

14.161 ANSWER:

 

                   (a)     r = 0.833

                   (b)    Lq = 3.788

                   (c)     Wq = 0.152 hours or 9.09 minutes

                   (d)    Yes, he has met that goal: time spent being served: 0.066 hours; time spent waiting: 0.152 hours.

                   (e)     Utilization factor is 0.833. Utilized time = 0.833(8 hours per day)(2 workers) = 13.33 hours

                            Nonutilized time in hours is given by: 16 – 13.33 = 2.67 hours @ 160 minutes.

                            He did not meet this goal.

                   (f)     Arrival rate would have to be approximately 27.2 persons per hour.