Deck 16: Computer Simulation With Crystal Ball

Question 1

The negative binomial distribution describes the number of trials until an event occurs n times.

Answer 1

True

Question 2

The custom distribution in Crystal Ball allows only discrete distributions to be entered.

Answer 2

False

Question 3

A forecast cell refers to a random input cell.

Answer 3

False

Question 4

The distribution used for the assumption cells is one of the options to be set in the Run Preferences for Crystal Ball.

Question 5

The three- and four-parameter distributions provide the most flexibility when trying to fit a curve to a situation.

Question 6

The sensitivity chart in Crystal Ball indicates the increase in the forecast cell value per unit increase in the assumption cell.

Question 7

The binomial distribution describes the number of times an event occurs in a fixed number of trials.

Question 8

The exponential distribution is widely used to describe the time between random events.

Question 9

The triangular distribution has a fixed upper and lower bound.

Question 10

Crystal Ball can be used to fit a discrete distribution to data.

Question 11

The Weibull and beta distribution are examples of two-parameter distributions.

Question 12

The normal distribution is a good choice when all values within a range are equally likely.

Question 13

The geometric distribution describes the number of times an event occurs in a fixed number of trials.

Question 14

A danger of using the lognormal distribution is that values can fall below zero.

Question 15

Increasing the number of trials increases the accuracy of a simulation.

Question 16

The mean standard error gives an indication of the accuracy of the estimated mean.

Question 17

A danger of using the normal distribution is that values can fall below zero.

Question 18

The number of trials is one of the options to be set in the Run Preferences for Crystal Ball.

Question 19

The normal distribution has a fixed upper and lower bound.

Question 20

The sensitivity chart in Crystal Ball indicates how strongly various assumption cells influence the forecast cell.

Question 21

Which of the following charts shows a histogram giving the relative frequency of the various output values in the forecast cell?

A)Frequency chart.
B)Statistics table.
C)Percentiles table.
D)Cumulative chart.
E)Reverse cumulative chart.

Question 22

The Decision Table tool in Crystal Ball can be used to systematically investigate a set of values for a decision variable in a simulation model.

Question 23

A trend chart shows the trend in profit values from trial to trial.

Question 24

OptQuest can not handle constraints in a simulation model.
Multiple Choice Questions

Question 25

OptQuest is guaranteed to find the optimal solution to a simulation problem.

Question 26

Which of the following provide the mean,median,standard deviation,range,etc.for the forecast cell in Crystal Ball.

A)Frequency chart.
B)Statistics table.
C)Percentiles table.
D)Cumulative chart.
E)Reverse cumulative chart.

Question 27

When applying simulation to an inventory problem,which of the following is the most appropriate choice for the forecast cell.

A)The total profit.
B)The holding cost per unit.
C)The demand.
D)All of the above.
E)None of the above.

Question 28

The more trials that are run,the lower the mean standard error will become.

Question 29

Which chart indicates the trend in forecast values as a particular decision variable is varied?

A)Frequency chart.
B)Trend chart.
C)Cumulative chart.
D)Reverse cumulative chart.
E)None of the above.

Question 30

Crystal Ball can be used to fit a continuous distribution to data.

Question 31

Which of the following is a random input cell in Crystal Ball?

A)An assumption cell.
B)A decision variable.
C)A forecast cell.
D)An output cell.
E)None of the above.

Question 32

The Solver Table can be used by Crystal Ball to systematically investigate a set of values for a decision variable in a simulation model.

Question 33

Which of the following is not a characteristic of the normal distribution?

A)Some value is the most likely.
B)Values closest to the mean are more likely.
C)It must be symmetric.
D)Values cannot fall below zero.
E)Extreme values are possible,but rare.

Question 34

Which of the following is not a step required to perform a simulation with Crystal Ball?

A)Define the random input cells.
B)Define the output cells to forecast.
C)Set the run preferences.
D)Develop the spreadsheet model.
E)All are steps required to perform a simulation with Crystal Ball.

Question 35

A distribution is chosen from the Distribution Gallery for which type of cell?

A)An assumption cell.
B)A decision variable.
C)A forecast cell.
D)An output cell.
E)None of the above.

Question 36

The cell that represents the output of a computer simulation is referred to as:

A)an assumption cell.
B)a decision variable.
C)a forecast cell.
D)a data cell.
E)None of the above.

Question 37

Which of the following are advantages of computer simulation over analytical methods like PERT/CPM for predicting the probability that a project will complete by a deadline?

A)It does not need to make as many simplifying assumptions.
B)It is more flexible about which probability distributions can be used.
C)It provides a solution more quickly.
D)All of the above.
E)a and b only.

Question 38

The sensitivity chart conveys which of the following?

A)The relative frequency of various forecast cell values.
B)The increase in profit per unit increase in an assumption cell.
C)It indicates how strongly various assumption cells influence the forecast cell.
D)The mean profit.
E)None of the above.

Question 39

When applying simulation to an inventory problem,which of the following would be an assumption cell?

A)The total profit.
B)The holding cost per unit.
C)The demand.
D)All of the above.
E)None of the above.

Question 40

Which of the following is not one of the charts or tables provided by Crystal Ball?

A)Frequency chart.
B)Statistics table.
C)Reverse frequency chart.
D)Cumulative chart.
E)Percentiles table.

Question 41

Which of the following distributions is widely used to describe the time between random events?

A)Uniform distribution.
B)Exponential distribution.
C)Poisson distribution.
D)Normal distribution.
E)None of the above.

Question 42

Which of the following is not a characteristic of the uniform distribution?

A)It has a fixed minimum value.
B)It has a fixed maximum value.
C)Some value is the most likely.
D)All of the above are characteristic of the uniform distribution.
E)None of the above are characteristic of the uniform distribution.

Question 43

Which of the following distributions describes the number of times an event occurs during a given period of time or space?

A)Uniform distribution.
B)Exponential distribution.
C)Poisson distribution.
D)Normal distribution.
E)None of the above.

Question 44

The custom distribution can be used for which of the following types of random values?

A)Sets of discrete values.
B)A range of discrete values.
C)A continuous distribution.
D)Combinations of a,b,and c.
E)All of the above.

Question 45

Which of the following are three-parameter distributions?

A)Weibull distribution.
B)Normal distribution.
C)Beta distribution.
D)All of the above.
E)a and c only.

Question 46

Which of the following is not a characteristic of the lognormal distribution?

A)Some value is the most likely.
B)It is negatively skewed (above the mean more likely).
C)Values cannot fall below zero.
D)Extreme values (high end only)are possible,but rare.
E)All of the above are characteristic of the lognormal distribution.

Question 47

Which of the following distributions describes the number of trials until an event occurs?

A)Binomial distribution.
B)Geometric distribution.
C)Negative binomial distribution.
D)Poisson distribution.
E)None of the above.

Question 48

Which of the following distributions describes the number of times an event occurs in a fixed number of trials?

A)Binomial distribution.
B)Geometric distribution.
C)Negative binomial distribution.
D)Poisson distribution.
E)None of the above.

Question 49

The Decision Table tool can simultaneously vary up to how many different decision variables?

A)1
B)2
C)3
D)4
E)Any number of decision variables.

Question 50

OptQuest can be used to simultaneously optimize up to how many decision variables?

A)1
B)2
C)3
D)4
E)Many decision variables can be optimized simultaneously.

Question 51

Which of the following is not a characteristic of the triangular distribution?

A)Some value is the most likely.
B)Values close to the most likely value are more common.
C)The most likely value is the mean.
D)It can be asymmetric.
E)It has a fixed upper and lower bound.

Question 52

Which of the following distributions describes the number of trials until an event occurs n times?

A)Binomial distribution.
B)Geometric distribution.
C)Negative binomial distribution.
D)Poisson distribution.
E)None of the above.

Question 53

Which of the following is not a good choice for run preferences when using OptQuest?

A)500 trials.
B)Using a different sequence of random numbers.
C)Latin Hypercube sampling method.
D)Update forecast windows and check precision control every 50 trials.
E)All are good choices when using OptQuest.