Question 1

A conditional probability of A given B is written in probability notation as ____________________.

Accepted Answer

The answer of A conditional probability of A given B...

Question 2

If either event A or event B must occur, they are called mutually exclusive.

Accepted Answer

A) True 
 B)False

Question 3

Suppose A and B are two mutually exclusive events for which P(A) = 0.30 and P(B) = 0.40.
a.
Find P(A and B).
b.
Find P(A or B).
c.
Are A and B independent events? Explain using probabilities.

Accepted Answer

The answer of Suppose A and B are two mutually...

Question 4

The collection of all the possible outcomes of a random experiment is called a sample space.

Accepted Answer

A) True 
 B)False

Question 5

If P(A) = .30, P(B) = .60, and P(A and B) = .20, then P(A|B) = .40.

Accepted Answer

A) True 
 B)False

Question 6

Tea and Seltzer
Suppose 55 percent of adults drink tea, 45 percent drink seltzer, and 10 percent drink both.
-{Tea and Seltzer Narrative} What is the probability that a randomly chosen adult drinks seltzer or tea or both?

Accepted Answer

The answer of Tea and Seltzer
Suppose 55 percent of adults...

Question 7

GPA and Class
A college professor classifies his students according to their grade point average (GPA) and their class rank.GPA is on a 0.0-4.0 scale, and class rank is defined as the under class (freshmen and sophomores) and the upper class (juniors and seniors).One student is selected at random.
 
-{GPA and Class Narrative} What is the probability that the student is in the lower class?

Accepted Answer

The answer of GPA and Class
A college professor classifies his...

Question 8

The probability of the intersection of two events A and B is denoted by P(A and B) and is called the:

Accepted Answer

A)  marginal probability 
B)  joint probability 
C)  conditional probability of A given B 
D)  conditional probability of B given A

Question 9

Tea and Seltzer
Suppose 55 percent of adults drink tea, 45 percent drink seltzer, and 10 percent drink both.
-{Tea and Seltzer Narrative} What is the probability that a randomly chosen adult doesn't drink tea or seltzer?

Accepted Answer

The answer of Tea and Seltzer
Suppose 55 percent of adults...

Question 10

Hobby Shop Sales
Sales records of a hobby shop showed the following number of radio controlled trucks sold weekly for each of the last 50 weeks.
 
-{Hobby Shop Sales Narrative} What is the probability of selling at least two trucks in any given week?

Accepted Answer

The answer of Hobby Shop Sales
Sales records of a hobby...

Question 11

If you roll a balanced die 50 times, you should expect an even number to appear:

Accepted Answer

A)  on every other roll. 
B)  exactly 50 times out of 100 rolls. 
C)  25 times on average, over the long term. 
D)  All of these choices are true.

Question 12

Messenger Service
Three messenger services deliver to a small town in Oregon.Service A has 60% of all the scheduled deliveries, service B has 30%, and service C has the remaining 10%.Their on-time rates are 80%, 60%, and 40% respectively.Define event O as a service delivers a package on time.
-{Messenger Service Narrative} If a package was delivered on time, what is the probability that it was service C?

Accepted Answer

The answer of Messenger Service
Three messenger services deliver to a...

Question 13

Messenger Service
Three messenger services deliver to a small town in Oregon.Service A has 60% of all the scheduled deliveries, service B has 30%, and service C has the remaining 10%.Their on-time rates are 80%, 60%, and 40% respectively.Define event O as a service delivers a package on time.
-{Messenger Service Narrative} If a package was delivered 40 minutes late, what is the probability that it was service C?

Accepted Answer

The answer of Messenger Service
Three messenger services deliver to a...

Question 14

Drunk Drivers
Six hundred accidents that occurred on a Saturday night were analyzed.Two items noted were the number of vehicles involved and whether alcohol played a role in the accident.The numbers are shown below:
 
-{Drunk Drivers Narrative} If alcohol was not involved, what proportion of the accidents were single vehicle?

Accepted Answer

The answer of Drunk Drivers
Six hundred accidents that occurred on...

Question 15

Cysts
After researching cysts of a particular type, a doctor learns that out of 10,000 such cysts examined, 1,500 are malignant and 8,500 are benign.A diagnostic test is available which is accurate 80% of the time (whether the cyst is malignant or not).The doctor has discovered the same type of cyst in a patient.
-{Cysts Narrative} In the absence of any test, what is the probability that the cyst is malignant?

Accepted Answer

The answer of Cysts
After researching cysts of a particular type,...

Question 16

Cysts
After researching cysts of a particular type, a doctor learns that out of 10,000 such cysts examined, 1,500 are malignant and 8,500 are benign.A diagnostic test is available which is accurate 80% of the time (whether the cyst is malignant or not).The doctor has discovered the same type of cyst in a patient.
-{Cysts Narrative} In the absence of any test, what is the probability that the cyst is benign?

Accepted Answer

The answer of Cysts
After researching cysts of a particular type,...

Question 17

Equity Loan Rates
A survey of banks estimated the following probabilities for the interest rate being charged on a equity loan based on a 30-year loan, based on past records.
 
-{Equity Loan Rates Narrative} If a bank is selected at random from this distribution, what is the probability that the interest rate charged on a home loan exceeds 7.0%?

Accepted Answer

The answer of Equity Loan Rates
A survey of banks estimated...

Question 18

Club Members
A survey of a club's members indicates that 50% own a home, 80% own a car, and 90% of the homeowners who subscribe also own a car.
-{Club Members Narrative} What is the probability that a club member owns a car or a house, or both?

Accepted Answer

The answer of Club Members
A survey of a club's members...

Question 19

Drunk Drivers
Six hundred accidents that occurred on a Saturday night were analyzed.Two items noted were the number of vehicles involved and whether alcohol played a role in the accident.The numbers are shown below:
 
-{Drunk Drivers Narrative} If multiple vehicles were involved, what proportion of accidents involved alcohol?

Accepted Answer

The answer of Drunk Drivers
Six hundred accidents that occurred on...

Question 20

If P(A and B) = 1, then A and B must be mutually exclusive.

Accepted Answer

A) True 
 B)False

Exam 6: Probability

A conditional probability of A given B is written in probability notation as ____________________.

If either event A or event B must occur, they are called mutually exclusive.

Suppose A and B are two mutually exclusive events for which P(A) = 0.30 and P(B) = 0.40. a. Find P(A and B). b. Find P(A or B). c. Are A and B independent events? Explain using probabilities.

The collection of all the possible outcomes of a random experiment is called a sample space.

If P(A) = .30, P(B) = .60, and P(A and B) = .20, then P(A|B) = .40.

Tea and Seltzer Suppose 55 percent of adults drink tea, 45 percent drink seltzer, and 10 percent drink both. -{Tea and Seltzer Narrative} What is the probability that a randomly chosen adult drinks seltzer or tea or both?

The probability of the intersection of two events A and B is denoted by P(A and B) and is called the:

Tea and Seltzer Suppose 55 percent of adults drink tea, 45 percent drink seltzer, and 10 percent drink both. -{Tea and Seltzer Narrative} What is the probability that a randomly chosen adult doesn't drink tea or seltzer?

Hobby Shop Sales Sales records of a hobby shop showed the following number of radio controlled trucks sold weekly for each of the last 50 weeks. -{Hobby Shop Sales Narrative} What is the probability of selling at least two trucks in any given week?

If you roll a balanced die 50 times, you should expect an even number to appear:

Club Members A survey of a club's members indicates that 50% own a home, 80% own a car, and 90% of the homeowners who subscribe also own a car. -{Club Members Narrative} What is the probability that a club member owns a car or a house, or both?

If P(A and B) = 1, then A and B must be mutually exclusive.