Operations MGMT Final Quizzes 11 16 13

The standard normal distribution has a mean of one and a standard deviation of zero.

True

False

False

________ is a measure of the dispersion of random variable values about the expected value or mean.

Standard deviation

Sample mean

Population mean

Expected value

Standard Deviation

The area under the normal curve represents the probability, and the total area under the curve sums to:

A) 0

B) 0.5

C) 1

D) 2

1

The ________ and variance are derived from a subset of the population data and are used to make inferences about the population.

A) population variance

B) population standard deviation

C) population mean

D) sample mean

Sample mean

Under the normal curve, the area between z = 1 and z = -2 includes approximately ________ of the values.

A) 98%

B) 95%

C) 85%

D) 82%

82%

For the normal distribution, the mean plus and minus 1.96 standard deviations will include what percent of the observations?

A) 84%

B) 90%

C) 95%

D) 97%

95%

The weight of a jar of jelly is normally distributed with a mean of 16 oz and a standard deviation of 0.02 oz. What is the probability that a jar of jelly contains less than 16 oz?

A) .1915

B) .3085

C) .5000

D) .7257

.5

For some values of Z, the probability that a standard normal variable is below Z is 0.3783. The value of Z is:

A) -0.81

B) -0.31

C) 0.82

D) 1.55

-0.31

When we use the chi-square test for normality, the observed frequency for each group should be at least 5.

True

False

False

3

Carrying costs include storage costs, interest, and depreciation.

True

False

True

Ordering costs include transportation, shipping, and inspection.

True

False

True

Shortage costs include loss of customer goodwill.

True

False

True

If order quantity is increased, annual holding cost ________, annual order cost ________, and change in annual total cost ________.

decreases, increases, is positive

decreases, increases, cannot be determined

increases, decreases, is negative

increases, decreases, cannot be determined

increases, decreases, cannot be determined

The diagram above represents which type of inventory model?

Economic Order Quantity (EOQ)

EOQ with Noninstantaneous Receipt

Fixed Period Model

EOQ model with shortages

EOQ with Noninstantaneous Receipt

The slope of the line labeled "B" in the diagram is

rate of inventory demand.

production rate.

shipping rate.

production rate minus rate of inventory demand.

production rate minus rate of inventory demand.

The slope of the line labeled "A" in the diagram is

order rate.

rate of inventory demand.

production rate.

production rate minus rate of inventory demand.

production rate.

The slope of the line labeled "C" in the diagram is

order rate.

rate of inventory demand.

production rate.

shipping rate.

rate of inventory demand

The interval labeled "E" in the diagram is

production cycle.

production run length.

shipping lead time.

inventory fill rate.

production cycle.

The interval labeled "D" in the diagram is

production cycle.

order receipt period.

shipping lead time.

inventory fill rate.

order receipt period.

The calling population is the source of customers.

True

False

True

The service rate is the average time it takes to serve a customer.

True

False

False

The basic single-server queuing model assumes an infinite calling population.

True

False

True

All single-server queuing models require the utilization factor to be less than 1.

True

False

True

In the basic single-server waiting line system, we assume the arrival rate follows a/an ______ distribution, and assume the service time follows a/an _______ distribution.

Normal, Normal

Poisson, Exponential

Poisson, Constant

Normal, Constant

Poisson, Exponential

If it takes 5 minutes to serve a customer at a fast food restaurant the service rate is ________customers/hour.

12

The arrival rate is the

time between arrivals to the service facility.

rate items arrive at the server after being in the queue.

rate of arrivals to the service facility.

time a customer spends in line.

rate of arrivals to the service facility.

Queuing discipline refers to

the reason waiting occurs in underloaded systems.

the order in which customers are processed.

the willingness of customers to wait in line.

how constant the interarrival times are.

the order in which customers are processed.

Constant service times occur with

machinery.

well-trained employees.

service processes.

assembly processes.

machinery.

A single-server queuing system has an average time between arrivals of 20 minutes and a service time of 10 minutes each. Assuming Poisson arrivals and exponential service times, the utilization factor is approximate:

0.25

0.33

0.50

2.0

0.5