Data Analysis for Managers Chapter 5

Corky and Lori process purchase orders for Acme Inc. Lori processes 60% of the purchase orders; Corky processes 40% of the purchase orders. 5% of Lori's purchase orders have errors and 2.5% of Corky's purchase orders have errors. A purchase order has an error; the probability that Lori processed the erroneous purchase order is

.75

Kareem is trying to decide which college to attend full time next year. Kareem believes there is a 55% chance that he will attend State College and a 33% chance that he will attend Northern University. The probability that Kareem will attend either State or Northern is

.88

The event A cannot occur if the P(A) =

0

The sportsbook at the High Roller Casino put the odds of a certain baseball team to win the World Series at 1:25 (1 to 25). Based on those odds, what is the probability that this baseball team will win the World Series?

0.0385

The probability of an employee getting a promotion is 0.2. The probability of an employee having an MBA is 0.3. The probability of an employee getting a promotion given that the employee has an MBA is 0.28. What is the probability that an employee has an MBA and gets a promotion?

0.084

The probability of randomly selecting a "spade" from a deck of cards is

0.25

A coach observes Tom making 10 free throws out of his last 30 attempts. Using the empirical approach, the coach assigns a probability of ______ to Tom making his next free throw. (Round probability to one decimal place.)

0.3

The probability of a customer ordering popcorn at the movie theater is .4. The probability of a customer ordering a drink at the movie theater is .65. The probability of a customer ordering popcorn and a drink is .3. If a customer has already ordered a drink, what is the probability the customer will order popcorn?

0.46

80% of companies ship their products by truck. 50% of companies ship their product by rail. 60% of companies ship by either truck or rail. What is the probability that a company ships by truck and rail?

0.7

The probability of Anthony being on time for work is 0.9. The probability that Anthony will take the train to work is 0.8. The probability that Anthony will be on time for work if he took the train is 0.95. The probability that Anthony is on time for work and took the train is

0.76

82% of companies ship their products by truck. 47% of companies ship their product by rail. 40% of companies ship by truck and rail. What is the probability that a company ships by truck or rail?

0.89

The sum of the probabilities of all the outcomes in the sample space is

1

A restaurant manager has 10 wait staff on duty but business has slowed down for the night and she needs to let 4 of the staff go home. How many different ways could she choose which 4 get to leave early?

210

Mike is placing a bet on an upcoming horse race in which 7 horses are running. Mike places a trifecta bet that wins only if he correctly picks the first, second, and third place horses in order. There are ______ possible outcomes for the first 3 horses in the correct order.

210

A festival has become so popular that it must limit the number of tickets it issues. People who hope to attend the festival send in a request for tickets, and requests are filled by random selection. Only 21% of the ticket requests are fulfilled. What are the odds of not receiving a ticket for a random applicant?

3.76 to 1

When determining P(B|A) knowing only P(A|B) and P(A|B'), _________ Theorem can be very helpful.

Bayes'

Which of the following events are mutually exclusive?

Being on time and being late for an appointment. Rolling an odd number and an even number on the same roll of a die.

The relative frequency of an event is used to calculate what type of probability?

Empirical

______ data is collected through observation.

Empirical

The three ways of assigning probability are

Empirical, classical, subjective

Consider rolling two dice. Which of the following describe two events that are collectively exhaustive?

Event 1: Rolling an even number. Event 2: Rolling an odd number. Event 1: A value of 6 or more. Event 2: A value of 8 or less. Event 1: A value of 7 or more. Event 2: A value of 6 or less.

Using the multiplication rule, the joint probability of event A and event B is computed by multiplying the conditional probability of event A given event B by the probability of

Event B

Mutually exclusive events

Events that cannot both occur at the same time

True or false: 0! = 0

False

True or false: Define event A = {1, 2, 3, 4} and event B = {2, 3, 6, 7}. A ∪ B = {2, 3}

False

True or false: The probability of winning a lottery is .0000000012. The Law of Large Numbers says that because this probability is so small, no one should ever win a lottery.

False

True or false: Tree diagrams are rarely used in business planning.

False

If two events do not affect each of their individual probabilities then the events are ______ events.

Independent

The multiplication rule is used to calculate what type of probability?

Joint

How many outcomes of an experiment constitute a simple event?

One

If an event is getting a letter grade of A in your statistics class, what is the complement of receiving an A?

Receiving any grade except an A.

A softball coach believes that Laurie has a .3 probability of getting a hit against a left-handed pitcher that Laurie has never batted against before. The .3 probability that the coach has assigned is what type of probability?

Subjective

Which of the following are examples of conditional probabilities?

The probability of Angel going to the movie, given that Derrick is going to the movie. If Neil has already purchased groceries, then the probability of Colleen purchasing groceries.

A prior probability for event A is the ____________ probability whereas the posterior probability of event A is the _____________ probability.

Unconditional, conditional

A travel web site wants to provide information comparing hotel costs versus the quality ranking of the hotel for hotels in New York City. One way to summarize this data would be

a contingency table.

If an experiment is selecting a card from a deck of cards, then the sample space is

all the cards in the deck.

Binary events are those that

are collectively exhaustive are mutually exclusive

A probability that can be deduced through logical reasoning before an experiment is performed is what type of probability?

classical

Events are considered __________ _____________ if the union of these events is the entire sample space.

collectively exhaustive

For any given event, the sum of the probability of that event and the probability of its ________ must equal one.

complement

A ________ probability is the probability of an event given that another event has already occurred.

conditional

The probability of Murali going to the coffee shop is 0.7. The probability of Connie going to the coffee shop is 0.4. If Murali goes to the coffee shop, the probability of Connie going to the coffee shop is 0.48. The events Murali going to the coffee shop and Connie going to the coffee shop are

dependent

Probabilities that are estimated from observed frequencies are called

empirical

A subset of the sample space is a/an

event

The probability that a customer will purchase a product is 0.15. The probability that a customer is a male is 0.5. The probability that a customer is a male and will purchase a product is 0.075. The events purchasing a product and being a male are

independent

Define event A = {1, 2, 3, 4} and event B = {6, 7, 8}. A ∩ B =

null set

The __________ formula is used to determine the number of ways to arrange x objects from a group of n objects where the order of the objects matters.

permutation

A numerical value that measures the likelihood of an uncertain event occurring is a

probability

To calculate a union for two mutually exclusive events

simply add the individual probabilities of the two events.

Suppose in a population of adults there are 10% that are avid fly fishermen/women. If we were to choose a random sample of 10 adults from this population the law of large numbers says

that the percent of fishermen/women in this sample might not equal 10% but as the sample gets larger the percent will get closer to 10%.

Contingency tables are useful to analyze

the results of a survey. relative frequencies

Bayes' _______ is used to revise probabilities when one has new _______

theorem/rule, information/data

To calculate a joint probability from a contingency table, the frequency of each cell is divided by the

total number of outcomes in the sample space.

A _______ diagram can help a business planner visualize all possibles outcomes of a decision.

tree

The _______ of two events, A and B, contains all the outcomes in either A or B or both A and B.

union

Probability values range from ______ to ______.

zero, one

Define event A = {1, 2, 3, 4} and event B = {2, 3, 6, 7}. A ∪ B =

{1, 2, 3, 4, 6, 7}

Define event A = {1, 2, 3, 4} and event B = {2, 3, 6, 7}. A ∩ B =

{2,3}

Which of the following sample spaces best describes the mode of transportation one might take to work each day?

{car, bus, bike, train}