FMIS 3301 QUIZ 4
1.
A single vending machine serves incoming customers.
The time between arrivals (T
a
) is 2
minutes with standard deviation of 4 minutes, and the machine can process 120 transactions per
hour at a constant rate.
What is the mean time in seconds that a customer spends in the queue?
* a.
20
b. 50
c. 80
d.
0.333
e. 12
T
p
= 30s
R
a
= 30/hr
U=30/120 = 0.25 T
w
= 30*(0.25/0.75)*(2) = 20s
2.
What would be the mean time in the queue if the single machine is replaced with two machines
which can process 60/hour each?
a.
0.18 hours
*b. 11 sec
c. 3 min
d.
71 sec
e. 1 min.
T
p
= 60s
R
a
= 30/hr
U=30/120 = 0.25 T
w
= 30*(0.25
1.449
/0.75)*(2) = 30*0.179*2=10.7s
3.
At a process, the average processing time is 35 seconds, with a standard deviation of 14 seconds.
What is the coefficient of variation of processing time?
a.
0.67
b. 2.5
c.
0.16
*d.
0.4
(14/35)
e. Not enough data
4.
OnCall Music receives orders by: 1 mail, 2telephone, 3internet site, and 4 email.
The hourly
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '09
 Lievano
 Standard Deviation, Capacity utilization

Click to edit the document details