QUESTION 20 (This problem description is for Questions 14, 15, 16, 17, 18, 19, 20, 21, 22) Tom, a college student, has taken a job as customer service representative in the computer department of a local department store to pay his rent. His only responsibility is to answer telephone calls for the department, most of which are inquiries about store hours and product availability. As Tom is the only person answering calls, the manager of the store is concerned about queuing (or waiting line) problems. Tom gets paid $15 per hour. Currently, the computer department receives an average of one call every 4 minutes, with standard deviation in this inter-arrival time of 4 minutes. Tom requires an average of 3 minutes to handle a call. The standard deviation of this activity time is 3 minutes. Assume that there is no limit on the number of customers that can be on hold, and customers do not hang up even if they are forced to wait for a long time. The telephone company charges $5.00 per hour for telephone lines whenever they are in use (either while the customer is in conversation with Tom or on hold because Tom is talking to some other customer). Find the average total number of customers in the system (who are talking with Tom or are waiting to talk with Tom). 4.75 3.75 2.75 3.00 2.25 QUESTION 21 (This problem description is for Questions 14, 15, 16, 17, 18, 19, 20, 21, 22) Tom, a college student, has taken a job as customer service representative in the computer department of a local department store to pay his rent. His only responsibility is to answer telephone calls for the department, most of which are inquiries about store hours and product availability. As Tom is the only person answering calls, the manager of the store is concerned about queuing (or waiting line) problems. Tom gets paid $15 per hour. Currently, the computer department receives an average of one call every 4 minutes, with standard deviation in this inter-arrival time of 4 minutes. Tom requires an average of 3 minutes to handle a call. The standard deviation of this activity time is 3 minutes. Assume that there is no limit on the number of customers that can be on hold, and customers do not hang up even if they are forced to wait for a long time. The telephone company charges $5.00 per hour for telephone lines whenever they are in use (either while the customer is in conversation with Tom or on hold because Tom is talking to some other customer) Find the average total cost per hour including the labor cost and phone line charge. $15 $20 $30 $45 $40 $25 QUESTION 22 (This problem description is for Questions 14, 15, 16, 17, 18, 19, 20, 21, 22) Tom, a college student, has taken a job as customer service representative in the computer department of a local department store to pay his rent. His only responsibility is to answer telephone calls for the department, most of which are inquiries about store hours and product availability. As Tom is the only person answering calls, the manager of the store is concerned about queuing (or waiting line) problems. Tom gets paid $15 per hour. Currently, the computer department receives an average of one call every 4 minutes, with standard deviation in this inter-arrival time of 4 minutes. Tom requires an average of 3 minutes to handle a call. The standard deviation of this activity time is 3 minutes. Assume that there is no limit on the number of customers that can be on hold, and customers do not hang up even if they are forced to wait for a long time. The telephone company charges $5.00 per hour for telephone lines whenever they are in use (either while the customer is in conversation with Tom or on hold because Tom is talking to some other customer). Last week, Tom didn't feel well so his service time (time to handle a call) became more volatile with the standard deviation of 6 (minutes) while he could maintain the same mean service time of 3 minutes. When it rains, it pours, customer calling behavior made it worse, the inter-arrival time of phone calls had the standard deviation of 8 minutes, but had the same mean of 4 minutes. Find the average walting time for a customer (before talking to Tom) last week. 40 minutes 32 minutes 30 minutes 18 minutes 36 minutes 20 minutes