Question 1

The grade distribution for a certain class is shown in the table.  What is the probability that a student selected at random from this class received a passing grade (D or better)? Round to two decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
The probability is __________.

Accepted Answer

The answer of The grade distribution for a certain class...

Question 2

If a ball is selected at random from an urn containing three red balls, five white balls, and two blue balls, what is the probability that it will be a white ball? Round to two decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
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The probability is __________.

Accepted Answer

The answer of If a ball is selected at random...

Question 3

A pair of fair dice is cast. What is the probability that the sum of the numbers shown uppermost is less than 6?
A) The probability is 
B) The probability is 
C) The probability is 
D) The probability is

Accepted Answer

The answer of A pair of fair dice is cast....

Question 4

According to data obtained from the National Weather Service, 387 of the 432 people killed by lightning in the United States between 1985 and 1992 were men. (Job and recreational habits of men make them more vulnerable to lightning.)
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Assuming that this trend holds in the future, what is the probability that a person killed by lightning is a male? Round to three decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
​
The probability is __________.

Accepted Answer

The answer of According to data obtained from the National...

Question 5

According to Mediamark Research, 85 million out of 179 million adults in the United States correct their vision by using prescription eyeglasses, bifocals, or contact lenses. (Some respondents use more than one type.)
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What is the probability that an adult selected at random from the adult population uses corrective lenses? Round to three decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
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The probability is __________ .

Accepted Answer

The answer of According to Mediamark Research, 85 million out...

Question 6

According to a survey of 176 retailers, 51% of them use electronic tags as protection against shoplifting and employee theft.
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If one of these retailers is selected at random, what is the probability that he or she uses electronic tags as anti-theft devices? Round to two decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
​
The probability is __________.

Accepted Answer

The answer of According to a survey of 176 retailers,...

Question 7

An opinion poll was conducted among a group of registered voters in a certain state concerning a proposition aimed at limiting state and local taxes. Results of the poll indicated that 31% of the voters favored the proposition, 37% were against it, and the remaining group were undecided. If the results of the poll are assumed to be representative of the opinions of the state's electorate, what is the probability that a registered voter selected at random from the electorate is undecided about the proposition?
A) 0.26
B) 0.28
C) 0.30
D) 0.32
E) 0.24

Accepted Answer

The percentage of voters who are undecided is 100% - 31% (in favor) - 37% (against) = 32%. Therefore, the probability that a randomly selected voter is undecided is 0.32.

Question 8

Consider the composition of a three-child family in which the children were born at different times. Assume that a girl is as likely as a boy at each birth. What is the probability that there are two girls and a boy in the family?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of Consider the composition of a three-child family...

Question 9

What is the probability of arriving at a traffic light when it is red if the red signal is flashed for 35 sec, the yellow signal for 5 sec, and the green signal for 60 sec?
A) The probability is 0.30
B) The probability is 0.35
C) The probability is 0.45
D) The probability is 0.40

Accepted Answer

The total cycle time of the traffic light is 35 (red) + 5 (yellow) + 60 (green) = 100 seconds. The red light is on for 35 seconds out of these 100 seconds. Therefore, the probability of arriving during the red light is 35/100 = 0.35.

Question 10

The grade distribution for a certain class is shown in the table.  What is the probability that a student selected at random from this class received a passing grade (D or better)?
A) The probability is 0.95
B) The probability is 0.99
C) The probability is 0.97
D) The probability is 0.93

Accepted Answer

The answer of The grade distribution for a certain class...

Question 11

A study conducted by the Corrections Department of a certain state revealed that 162,883 people out of a total adult population of 1,713,709 were under correctional supervision (on probation, parole, or in jail). What is the probability that a person selected at random from the adult population in that state is under correctional supervision?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of A study conducted by the Corrections Department...

Question 12

A study conducted by the Corrections Department of a certain state revealed that 166,756 people out of a total adult population of 1,714,697 were under correctional supervision (on probation, parole, or in jail).
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What is the probability that a person selected at random from the adult population in that state is under correctional supervision? Round to three decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
​
The probability is __________.

Accepted Answer

The answer of A study conducted by the Corrections Department...

Question 13

The number of cars entering a tunnel leading to an airport in a major city over a period of 200 peak hours was observed and the following data were obtained.

What is the probability that more than 600 cars will enter the airport tunnel during a peak hour?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of The number of cars entering a tunnel...

Question 14

In a sweepstakes sponsored by Gemini Paper Products, 100,000 entries have been received. If 2 grand prize, 5 first prizes, 35 second prizes, and 600 third prizes are to be awarded, what is the probability that a person who has submitted one entry will win a prize? Round to five decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
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The probability is __________.

Accepted Answer

The answer of In a sweepstakes sponsored by Gemini Paper...

Question 15

In a sweepstakes sponsored by Gemini Paper Products, 100,000 entries have been received. If 3 grand prize, 5 first prizes, 30 second prizes, and 400 third prizes are to be awarded, what is the probability that a person who has submitted one entry will win a prize?
A) The probability is 0.00508
B) The probability is 0.01138
C) The probability is 0.00438
D) The probability is 0.00445

Accepted Answer

The answer of In a sweepstakes sponsored by Gemini Paper...

Question 16

What is the probability of arriving at a traffic light when it is red if the red signal is flashed for 15 sec, the yellow signal for 5 sec, and the green signal for 55 sec? Round to two decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
​
The probability is __________.

Accepted Answer

The answer of What is the probability of arriving at...

Question 17

One light bulb is selected at random from a lot of 100 light bulbs, of which 6% are defective.
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What is the probability that the light bulb selected is defective? Round to two decimal places, if necessary, and be sure to express answer in decimal form, not as a percentage.
​
The probability is __________.

Accepted Answer

The answer of One light bulb is selected at random...

Question 18

In a survey conducted in 2007 of 970 adults 18 years old and older, the following question was asked: How are American companies doing on protecting the environment compared with companies in other countries? The results are summarized below:  If an adult in the survey selected at random, what is the probability that he or she said that American companies are equal or ahead on protecting the environment compared with companies in other countries? Round your answer to two decimal places.
A) 0.52
B) 0.45
C) 0.60
D) 0.65
E) 0.38

Accepted Answer

The answer of In a survey conducted in 2007 of...

Question 19

Let  be the sample space associated with an experiment having the following probability distribution:  Find the probability of the event  .
A) The probability is 0
B) The probability is 
C) The probability is 
D) The probability is

Accepted Answer

The answer of Let  be the sample space associated...

Question 20

Determine whether the given experiment has a sample space with equally likely outcomes. Two fair dice are cast, and the sum of the numbers appearing uppermost is recorded. 
A) yes
B) no

Accepted Answer

The outcomes of rolling two dice and summing the numbers are not equally likely because some sums can be achieved in more ways than others. For example, a sum of 7 can be achieved with six different combinations (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) while a sum of 2 can only be achieved with one combination (1+1).

Quiz 7: Probability

A pair of fair dice is cast. What is the probability that the sum of the numbers shown uppermost is less than 6?

Consider the composition of a three-child family in which the children were born at different times. Assume that a girl is as likely as a boy at each birth. What is the probability that there are two girls and a boy in the family?

What is the probability of arriving at a traffic light when it is red if the red signal is flashed for 35 sec, the yellow signal for 5 sec, and the green signal for 60 sec?

The grade distribution for a certain class is shown in the table. What is the probability that a student selected at random from this class received a passing grade (D or better) ?

The number of cars entering a tunnel leading to an airport in a major city over a period of 200 peak hours was observed and the following data were obtained. What is the probability that more than 600 cars will enter the airport tunnel during a peak hour?

In a sweepstakes sponsored by Gemini Paper Products, 100,000 entries have been received. If 3 grand prize, 5 first prizes, 30 second prizes, and 400 third prizes are to be awarded, what is the probability that a person who has submitted one entry will win a prize?

Let be the sample space associated with an experiment having the following probability distribution: Find the probability of the event .

Determine whether the given experiment has a sample space with equally likely outcomes. Two fair dice are cast, and the sum of the numbers appearing uppermost is recorded.