Question 1 The service times for a grocery store with one checkout line have a mean of 3 minutes and a standard deviation of 20 seconds.

Question 1

The service times for a grocery store with one checkout line have a mean of 3 minutes and a standard deviation of 20 seconds. Customer arrivals at the checkout stand follow a Poisson distribution. What type of system is it?

a. M/G/1

b. M/M/1

c. M/D/1

d. G/M/1

Question 2

One reason to use queuing models in business is

a. to maximize the number of service providers

b. to trade-off the cost of providing service and the cost of customer dissatisfaction

c. to minimize the cost of providing service

d. all of the above

Question 3

A company has recorded the following list of service rates (customers/hour) for one of its servers. What is the mean service time for this server?

Customers / hour: 4, 4, 5, 6, 5, 4, 3, 4, 3, 5, 5, 6

a. 1.11 min

b. 13.3 min

c. 0.22 min

d. 4.5 min

Question 4

The number of arrivals to a store follows a Poisson distribution with mean λ = 10/hour. What is the mean inter-arrival time?

a. 10 hours

b. 6 seconds

c. 6 minutes

d. 10 minutes

Question 5

If the arrival process is modeled as a Poisson random variable with arrival rate λ, then the average time between arrivals is

a. 1/λ2

b. σ

c. 1/λ

d. 1/μ

Question 6

Which type of queuing system are you likely to encounter at a grocery store?

a. Multiple waiting lines, single service station.

b. Single waiting line, single service station.

c. Multiple waiting lines, multiple service stations.

d. Single waiting line, multiple service stations.

Question 7

In the Kendall notation M/D/4, D stands for :

a. memoryless arrival distribution

b. memoryless arrival and departure distributions

c. deterministic departure distribution

d. none of the above

Question 8

In the Kendall notation M/G/4, G stands for :

a. memoryless arrival distribution

b. none of the above

c. general departure distribution

d. memoryless arrival and departure distributions

Question 9

For a Poisson random variable, λ represents the ____ number of arrivals per time period:

a. average

b. standard deviation of

c. minimum

d. maximum

Question 10

A Poisson distribution shape can be described as:

a. slightly skewed to the left.

b. skewed to the right.

c. discrete so it lacks any definable shape.

d. symmetric around the parameter λ.

Question 11

Which type of queuing system are you likely to encounter at an ATM?

a. Single waiting line, multiple service stations.

b. Single waiting line, single service station.

c. Multiple waiting lines, single service station.

d. Multiple waiting lines, multiple service stations.

Question 12

Which of the following is the typical operating characteristic for the probability an arriving unit has to wait for service?

a. Pn

b. P0

c. Pw

d. Wp

Question 13

The goal of discriminant analysis is:

a. none of these.

b. the develop a rule for predicting to what group a new observation is most likely to belong.

c. to develop a model to predict new dependent values.

d. to develop a rule for predicting how independent variable values predict dependent values.

Question 14

In the  step of data mining, a researcher attempts to estimate to which discrete group an observation belongs to:

a. classification

b. categorization

c. association/segmentation

d. prediction

Question 15

In the  step of data mining, a researcher attempts to form logical groupings of data in the set:

a. prediction

b. association/segmentation

c. categorization

d. classification

Question 16

Plots useful in data mining analysis can be accessed in Excel using the____ add-in:

a. XLMiner

b. Vusual Basic

c. Data Analysis

d. Charts

Question 17

Data mining tasks fall in the following categories:

a. classification, prediction, association

b. categorization, segmentation

c. prediction, association, mining

d. observation, categorization, association

Question 18

Technique(s) used in classification step of data mining include:

a. neural networks

b. all of the above

c. logistic regression

d. discriminant analysis

Question 19

Suppose that the correlation coefficient between X1 and X2 is equal to 1. This means that:

a. X1 and X2 are weakly and negatively correlated

b. X1 and X2 are weakly and positively correlated

c. X1 and X2 are perfectly negatively correlated

d. X1 and X2 are perfectly positively correlated

Question 20

The objective function in k-means clustering attempts to:

a. maximize the sum of between-cluster dispersions for all clusters

b. maximize the sum of within-cluster dispersions for all clusters

c. minimize the sum of within-cluster dispersions for all clusters

d. minimize the sum of between-cluster dispersions for all clusters