Question 1

Suppose you want to estimate the probability that a randomly selected customer at a particular grocery store will pay by credit card. Over the past 3 months, 70,600 purchases were made, and 22,200 of them were paid for by credit card. What is the estimated probability that a randomly selected customer will pay by credit card? ​

Accepted Answer

The estimated probability is calculated by dividing the number of purchases made by credit card by the total number of purchases: 22,200 / 70,600 = 0.3144.

Question 2

Two events are independent if they cannot occur simultaneously.

Accepted Answer

Two events are independent if the occurrence of one event does not affect the probability of the other event occurring. This is different from events not being able to occur simultaneously, which would be more related to mutually exclusive events.

Question 3

The event "A or B " consists of all of the outcomes in both of the events.

Accepted Answer

The event "A or B" consists of all the outcomes in either event, not both.

Question 4

If two events, A and B, are mutually exclusive, then  .

Accepted Answer

The answer of If two events, A and B, are...

Question 5

An event consisting of exactly one outcome is called a simple event.

Accepted Answer

A simple event is an event that has only one possible outcome.

Question 6

Each time a class meets, the professor selects one student at random to explain the solution to a homework problem. There are 60 students in the class, and no one ever misses class. Luke is one of these students. What is the probability that Luke is selected both of the next two times that the class meets? ​

Accepted Answer

The probability of Luke being selected in one class is 1/60. Since the selections are independent, the probability of him being selected in both classes is (1/60) * (1/60) = 1/3600 = 0.00028.

Question 7

Any collection of possible outcomes of a chance experiment is called a sample space.

Accepted Answer

The answer of Any collection of possible outcomes of a...

Question 8

The General Multiplication Rule states that  .

Accepted Answer

The answer of The General Multiplication Rule states that ...

Question 9

The General Addition Rule states that

Accepted Answer

The answer of The General Addition Rule states that ...

Question 10

The classical view of probability is based on the Law of Large Numbers.

Accepted Answer

The classical view of probability is based on the assumption of equally likely outcomes, not the Law of Large Numbers, which pertains to the stability of averages from large samples.

Question 11

Two events, E and F, are independent if  .

Accepted Answer

The answer of Two events, E and F, are independent...

Question 12

An airline reports that for a particular flight operating daily between Phoenix and Atlanta, the probability of an on-time arrival is 0.64. Give a relative frequency interpretation of this probability. ​

Accepted Answer

The relative frequency interpretation of a probability of 0.64 is that, in the long run, 64% of the flights between Phoenix and Atlanta will arrive on time.

Question 13

Suppose you want to estimate the probability that a patient will develop an infection while hospitalized at a particular hospital. In the past year, this hospital had 8,650 patients, and 812 of them developed an infection. What is the estimated probability that a patient at this hospital will develop an infection? ​

Accepted Answer

The answer of Suppose you want to estimate the probability...

Question 14

A large cable company reports that 70% of its customers subscribe to its cable TV service, 32% subscribe to its Internet service, and 87% subscribe to at least one of these two services. Use the given probability information to select a "hypothetical 1000" table. ​

Accepted Answer

The answer of A large cable company reports that 70%...

Question 15

Two events are said to be disjoint or mutually exclusive when they have no outcomes in common.

Accepted Answer

Disjoint or mutually exclusive events have no outcomes in common. If two events have outcomes in common, they are not disjoint.

Question 16

A rental car company offers two options when a car is rented. A renter can choose to pre-purchase gas or not and can also choose to rent a GPS device or not. Suppose that the events ​
A = event that gas is pre-purchased
B = event that a GPS is rented
​
Are independent with P(A) = 0.35 and P(B) = 0.50.
​
Select a "hypothetical 1000" table with columns corresponding to whether or not gas is pre-purchased and rows corresponding to whether or not a GPS is rented.
​

Accepted Answer

The answer of A rental car company offers two options...

Question 17

A deck of 52 cards is mixed well, and 5 cards are dealt. It can be shown that (disregarding the order in which the cards are dealt) there are 2,598,960 possible hands, of which only 4 hands are royal flushes. (A royal flush is a hand consisting of 10, J, Q, K, and A, all of the same suit). ​
What is the probability that a hand will be a royal flush?
​

Accepted Answer

The answer of A deck of 52 cards is mixed...

Question 18

The faces of a twelve-sided die are numbered with the numbers 1 through 12. If you roll this die 600 times, how many nines do you expect to roll? ​

Accepted Answer

The expected value for any specific outcome of a twelve-sided die is the total number of rolls divided by the number of faces. Therefore, $600 \div 12 = 50$.

Question 19

A chance experiment is any activity or situation in which there is uncertainty concerning which of two or more possible outcomes will result.

Accepted Answer

This is the definition of a chance experiment.

Question 20

The probability of an event E can always be computed using the formula,
​

Accepted Answer

The answer of The probability of an event E can...

Quiz 5: Probability

Two events are independent if they cannot occur simultaneously.

The event "A or B " consists of all of the outcomes in both of the events.

If two events, A and B, are mutually exclusive, then .

An event consisting of exactly one outcome is called a simple event.

Any collection of possible outcomes of a chance experiment is called a sample space.

The General Multiplication Rule states that .

The General Addition Rule states that

The classical view of probability is based on the Law of Large Numbers.

Two events, E and F, are independent if .

An airline reports that for a particular flight operating daily between Phoenix and Atlanta, the probability of an on-time arrival is 0.64. Give a relative frequency interpretation of this probability. ​

A large cable company reports that 70% of its customers subscribe to its cable TV service, 32% subscribe to its Internet service, and 87% subscribe to at least one of these two services. Use the given probability information to select a "hypothetical 1000" table. ​

Two events are said to be disjoint or mutually exclusive when they have no outcomes in common.

The faces of a twelve-sided die are numbered with the numbers 1 through 12. If you roll this die 600 times, how many nines do you expect to roll? ​

A chance experiment is any activity or situation in which there is uncertainty concerning which of two or more possible outcomes will result.

The probability of an event E can always be computed using the formula, ​

An airline reports that for a particular flight operating daily between Phoenix and Atlanta, the probability of an on-time arrival is 0.64. Give a relative frequency interpretation of this probability.

A large cable company reports that 70% of its customers subscribe to its cable TV service, 32% subscribe to its Internet service, and 87% subscribe to at least one of these two services. Use the given probability information to select a "hypothetical 1000" table.

The faces of a twelve-sided die are numbered with the numbers 1 through 12. If you roll this die 600 times, how many nines do you expect to roll?

The probability of an event E can always be computed using the formula,