Homework answers / question archive / Question1)A conditional probability P(B|A) is equal to its marginal probability P(B) if:               Question 2     Which Excel feature is an optimization technique that can maximize or minimize a quantity given a set of limitations or constraints? Question 3     A production process is known to produce a particular item in such a way that five percent of these are defective

Question1)A conditional probability P(B|A) is equal to its marginal probability P(B) if:               Question 2     Which Excel feature is an optimization technique that can maximize or minimize a quantity given a set of limitations or constraints? Question 3     A production process is known to produce a particular item in such a way that five percent of these are defective

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Question1)A conditional probability P(B|A) is equal to its marginal probability P(B) if:

 

 

 

Question 2

Which Excel feature is an optimization technique that can maximize or minimize a quantity given a set of limitations or constraints?

Question 3

A production process is known to produce a particular item in such a way that five percent of these are defective. If two items are randomly selected as they come off the production line, what is the probability that the second item will be defective?

Question 4

One purpose of regression is to understand the relationship between variables.

Question 5

A medium-term forecast is considered to cover what length of time?

Question 6

Scatter diagrams can be useful in spotting trends or cycles in data over time.

Question 7

Assume that you have an urn containing 10 balls of the following description:

4 are white (W) and lettered (L)
2 are white (W) and numbered (N)
3 are yellow (Y) and lettered (L)
1 is yellow (Y) and numbered (N)
 
If you draw a lettered ball (L), the probability that this ball is white (W) is 0.571.

Question 8

Consider the following payoff table that represents the profits earned for each alternative (A, B, and C) under the states of nature S1, S2, and S3.
                  S1        S2        S3
       A         $60      $145     $120          
       B         $75      $125     $110
       C         $95      $85       $130
 
Refer to the payoff table. What is the expected value of perfect information (EVPI)? Assume P(S1) = 0.5 and P(S2) = 0.25.

Question 9

A local ice cream shop sells 10,000 cones of vanilla-flavored ice cream each year. The cones are ordered from an outside supplier and it takes 5 days for each shipment of cones to arrive. Ordering costs are estimated at $15 per order. Carrying costs are $5 per cone per year. Assume that the ice cream shop is open 250 days a year. What is the average inventory of cones held in a given ordering cycle?

Question 10

A bakery buys sugar in 15-pound bags. The bakery uses 5000 bags of sugar each year. Carrying costs are $20 per bag per year. Ordering costs are estimated at $5 per order. Assume that the bakery is open 250 days a year and its daily demand is estimated at 20 bags. It takes 5 days for each order of sugar to be filled. What is the average inventory held in a given cycle?

Question 11

Consider the following gasoline data:

 

Referring to the information above, suppose we expect year 3 to have annual demand of 800. What is the forecast value for the first quarter in year 3?

 

Question 12

A bakery buys sugar in 15-pound bags. The bakery uses 5000 bags of sugar each year. Carrying costs are $20 per bag per year. Ordering costs are estimated at $5 per order. Assume that the bakery is open 250 days a year and its daily demand is estimated at 20 bags. It takes 5 days for each order of sugar to be filled. What is the optimal number of orders per year?

Question 13

The diagram below illustrates data with

 

 

Question 14

The classical method of determining probability is:

Question 15

If computing a causal linear regression model of Y = a + bX and the resultant r² is very near zero, then one would be able to conclude that:

Question 16

A local ice cream shop sells 10,000 cones of vanilla-flavored ice cream each year. The cones are ordered from an outside supplier and it takes 5 days for each shipment of cones to arrive. Ordering costs are estimated at $15 per order. Carrying costs are $5 per cone per year. Assume that the ice cream shop is open 250 days a year. What is the total cost of ordering and carrying the ice cream cones?

Question 17

Bob White is conducting research on monthly expenses for medical care, including over-the-counter medicine. His dependent variable is monthly expenses for medical care while his independent variable is number of family members. Below is his Excel output.



 

Based on the information above, the null hypothesis that the slope is zero can be rejected.

 

Question 18

Given the following distribution:

Outcome	Value of Random Variable	Probability
A	1	.4
B	2	.3
C	3	.2
D	4	.1

 
The expected value is 3.

Question 19

“The probability of event B, given that event A has occurred” is known as a __________ probability.

Question 20

The use of "expert opinion" is one way to approximate subjective probability values.

Question 21

An urn contains seven blue and three yellow chips. If the drawing of chips is done with replacement, what is the probability of drawing three yellow chips?

Question 22

A plant manager is considering buying additional stamping machines to accommodate increasing demand. The alternatives are to buy 1 machine, 2 machines, or 3 machines. The profits realized under each alternative are a function of whether their bid for a recent defense contract is accepted or not. The payoff table below illustrates the profits realized (in $000's) based on the different scenarios faced by the manager.
 
Alternative           Bid Accepted           Bid Rejected
Buy 1 machine              $10                           $5
Buy 2 machines            $30                           $4
Buy 3 machines            $40                           $2

Using the information above, which alternative should be chosen based on the criterion of realism with alpha = 0.8?

Question 23

Summing the error values in a regression model is misleading because negative errors cancel out positive errors.

Question 24

A controllable variable is also called:

Question 25

Arrivals in a university advising office during the week of registration are known to follow a Poisson distribution with an average of four people arriving each hour. What is the probability that exactly five people will arrive in the next hour?

Question 26

Bob White is conducting research on monthly expenses for medical care, including over-the-counter medicine. His dependent variable is monthly expenses for medical care while his independent variable is number of family members. Below is his Excel output.

 

 

Referring to the information above, the significance F-test, is this model a good prediction equation?

Question 27

Which of the following statement(s) is/are true regarding the advantages of mathematical modeling?

Question 28

If the assumptions of regression have been met, errors plotted against the independent variable will typically show patterns.

Question 29

In a scatter diagram, the dependent variable is typically plotted on the horizontal axis.

Question 30

Consider the following payoff table that represents the profits earned for each alternative (A, B, and C) under the states of nature S1, S2, and S3.
                  S1        S2        S3
       A         $60      $145     $120          
       B         $75      $125     $110
       C         $95      $85       $130
 
Refer to the payoff table. Using the expected monetary value (EMV) criterion, what is the highest attainable expected profit? Assume P(S1) = 0.5 and P(S2) = 0.25.

Question 31

A discrete random variable has a mean of 400 and a variance of 64. What is the standard deviation?

Question 32

When the smoothing constant α = 1, the exponential smoothing model is equivalent to the naïve forecasting model.

Question 33

A series of steps or procedures that are repeated is known as an algorithm.

Question 34

Given three statistically independent events (A,B,C), the joint probability of P(ABC) = P(A) × P(B) × P(C).

Question 35

Which of the following is true regarding a regression model with multicollinearity, a high r² value, and a low F-test significance level?

Question 36

Consider the following gasoline data:

 

 

Referring to the information above, what is the seasonal index for third quarter?

Question 37

A new young executive is perplexed at the number of interruptions that occur due to employee relations. She has decided to track the number of interruptions that occur during each hour of her day. Over the last month, she has determined that between 0 and 3 interruptions occur during any given hour of her day. The data is shown below.

Number of Interruptions in 1 hour	Probability
0 interruption	.4
1 interruptions	.3
2 interruptions	.2
3 interruptions	.1

On average, she should expect 1.0 interruptions per hour.

Question 38

The Department of Motor Vehicles (DMV) can service customers at a rate of 20 per hour (or 1/3 per minute) when it comes to license renewals. The service time follows an exponential distribution. What is the probability that it will take less than three minutes for a particular customer to get a license renewal?

Question 39

Saying that a set of events is mutually exclusive and collectively exhaustive implies that one and only one of the events can occur on any trial.

Question 40

A bakery buys sugar in 15-pound bags. The bakery uses 5000 bags of sugar each year. Carrying costs are $20 per bag per year. Ordering costs are estimated at $5 per order. Assume that the bakery is open 250 days a year and its daily demand is estimated at 20 bags. It takes 5 days for each order of sugar to be filled. What is the maximum inventory held in a given EOQ cycle?

Question 41

Which of the following is not a common pitfall of regression?

Question 42

In the exponential smoothing with trend adjustment forecasting method, missing something is the:

Question 43

If the standard deviation of demand is 10 and the desired service level is 0.90, then what is the safety stock?

Question 44

An urn contains seven blue and three yellow chips. If the drawing of chips is done with replacement, what is the probability of drawing a blue chip on the second draw given that a yellow chip was drawn on the first draw?

Question 45

The number of phone calls coming into a switchboard in the next five minutes will either be 0, 1, 2, 3, 4, 5, or 6. The probabilities are the same for each of these (1/7). If X is the number of calls arriving in a five-minute time period, what is the mean of X?

Question 46

Mutually exclusive events exist if only one of the events can occur on any one trial.

Question 47

Assume that you have an urn containing 10 balls of the following description:

 

Question 48

If the sale of ice cream and pizza are independent, then as ice cream sales decrease by 60 percent during the winter months, pizza sales will:

Question 49

A bakery buys sugar in 15-pound bags. The bakery uses 5000 bags of sugar each year. Carrying costs are $20 per bag per year. Ordering costs are estimated at $5 per order. Assume that the bakery is open 250 days a year and its daily demand is estimated at 20 bags. It takes 5 days for each order of sugar to be filled. What is the minimum inventory held in a given EOQ cycle?

Question 50

A __________ is a numerical statement about the likelihood that an event will occur.