New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
business
elementary statistics
Elementary Statistics 3rd Edition William Navidi, Barry Monk - Solutions
n = 30, p = 0.9, P(More than 27)In Exercises 17–26, determine the indicated probability for a binomial experiment with the given number of trials n and the given success probability p. Then find the mean, variance, and standard deviation.
The number of songs on a randomly chosen iPod In Exercises 17–26, determine whether the random variable described is discrete or continuous.
In Exercises 27–32, determine whether the table represents a discrete probability distribution. If not, explain why not. x P(x) 1 0.4 23 0.2 3 0.1 4 0.3
An environmental scientist obtains a sample of water from a pond that contains a certain type of bacteria at a concentration of 5 per milliliter.a. What is the probability that there will be exactly 12 bacteria in a 3-milliliter sample of water?b. Find the mean number of bacteria in a 3-milliliter
Match each TI-84 PLUS calculator command with the probability being calculated.a. 1 - binomcdf (n, p, 5)b. binompdf (n, p, 0)c. binompdf (n, p, 5)d. binomcdf (n, p, 5) - binompdf (n, p, 0)i. Probability of exactly 5 successes ii. Probability of more than 5 successes iii. Probability of no successes
In a recent year, there were approximately 250,000,000 registered motor vehicles in the United States. Of these, approximately 4% were involved in an accident during the year. Assume that a simple random sample of n = 200 vehicles is drawn. Use the Poisson approximation to the binomial distribution
In Exercises 27–32, determine whether the table represents a discrete probability distribution. If not, explain why not. P(x) 30 0.2 40 0.2 50 0.2 60 0.2 70 0.2
Match each TI-84 PLUS calculator command with the probability being calculated.a. binomcdf (n, p, 5)b. 1 - binompdf (n, p, 0)c. binomcdf (n, p, 5) - binomcdf (n, p, 2)d. binompdf (n, p, 1) + binompdf (n, p, 2)i. Probability of either 1 or 2 successes ii. Probability of at least one success iii.
A report from the Medical College of Georgia stated that the proportion of infants born with Down Syndrome is 0.0011. Assume a sample of 5000 births is studied.Use the Poisson approximation to the binomial distribution to compute the following:a. The probability that exactly 5 of the 5000 births
A student takes a true–false test that has 10 questions and guesses randomly at each answer. Let X be the number of questions answered correctly.a. Find P(4).b. Find P(Fewer than 3).c. To pass the test, the student must answer 7 or more questions correctly. Would it be unusual for the student to
In Exercises 27–32, determine whether the table represents a discrete probability distribution. If not, explain why not. x P(x) 2.1 0.1 2.2 0.1 2.3 0.1 2.4 0.1
Assume that events occurring in time follow a Poisson distribution with rate λ. Let T be the amount of time, in seconds, that elapses between two events. This exercise will show how to compute probabilities involving T.a. Let X be the number of events that occur in a 1-second interval. Show that
In Exercises 27–32, determine whether the table represents a discrete probability distribution. If not, explain why not. x P(x) 55 -0.3 65 0.6 75 0.4 85 0.2
A student takes a multiple-choice test that has 10 questions. Each question has four choices. The student guesses randomly at each answer.a. Find P(3).b. Find P(More than 2).c. To pass the test, the student must answer 7 or more questions correctly. Would it be unusual for the student to pass?
At Denver International Airport, 81% of recent flights have arrived on time. A sample of 12 flights is studied.a. Find the probability that all 12 of the flights were on time.b. Find the probability that exactly 10 of the flights were on time.c. Find the probability that 10 or more of the flights
In Exercises 27–32, determine whether the table represents a discrete probability distribution. If not, explain why not. x P(x) 100 0.2 200 0.3 300 0.5 400 0.4 500 0.1
In Exercises 27–32, determine whether the table represents a discrete probability distribution. If not, explain why not. x P(x) -4 0.35 -1 0.25 0 0.15 2 0.25
Of all the registered automobiles in Colorado, 8% fail the state emissions test. Twelve automobiles are selected at random to undergo an emissions test.a. Find the probability that exactly three of them fail the test.b. Find the probability that fewer than three of them fail the test.c. Find the
In Exercises 33–38, compute the mean and standard deviation of the random variable with the given discrete probability distribution. x P(x) 1 0.42 257 2 0.18 5 0.34 0.06
According to a report of the Nielsen Company, 76% of Internet searches used the Google search engine. Assume that a sample of 25 searches is studied.a. What is the probability that exactly 20 of them used Google?b. What is the probability that 15 or fewer used Google?c. What is the probability that
In Exercises 33–38, compute the mean and standard deviation of the random variable with the given discrete probability distribution. 4835 P(x) 0.15 13 0.23 15 0.25 18 0.27 19 0.10
In Exercises 33–38, compute the mean and standard deviationof the random variable with the given discrete probability distribution. x P(x) 4.5 0.33 69 0.11 7 0.21 9.5 0.35
In Exercises 33–38, compute the mean and standard deviation of the random variable with the given discrete probability distribution. x P(x) -3 0.10 0 0.17 1 0.56 3 0.17
A study conducted by the Pew Research Center reported that 58% of cell phone owners used their phones inside a store for guidance on purchasing decisions.A sample of 15 cell phone owners is studied.a. What is the probability that six or more of them used their phones for guidance on purchasing
The Agency for Healthcare Research and Quality reported that 53% of people who had coronary bypass surgery in a recent year were over the age of 65.Fifteen coronary bypass patients are sampled.a. What is the probability that exactly 9 of them are over the age of 65?b. What is the probability that
In Exercises 33–38, compute the mean and standard deviation of the random variable with the given discrete probability distribution. x P(x) 15 0.15 17 0.23 19 0.25 22 0.27 26 0.10
The Centers for Disease Control and Prevention reports that 25% of baby boys 6–8 months old in the United States weigh more than 20 pounds. A sample of 16 babies is studied.a. What is the probability that exactly 5 of them weigh more than 20 pounds?b. What is the probability that more than 6
The blood type O negative is called the ‘‘universal donor’’ type, because it is the only blood type that may safely be transfused into any person. Therefore, when someone needs a transfusion in an emergency and their blood type cannot be determined, they are given type O negative blood. For
The Statistical Abstract of the United States reported that 66% of students who graduated from high school in 2012 enrolled in college. Thirty high school graduates are sampled.a. What is the probability that exactly 18 of them enroll in college?b. What is the probability that more than 15 enroll
In Exercises 33–38, compute the mean and standard deviation of the random variable with the given discrete probability distribution. x P(x) 120 0.30 150 0.30 170 0.15 180 0.25
Fill in the missing value so that the following table represents a probability distribution. x 4 5 6 7 P(x) 0.3 ? 0.3 0.2
Fill in the missing value so that the following table represents a probability distribution. x 15 25 35 45 55 P(x) 0.25 0.15 ? 0.05 0.15
Let X represent the number of tires with low air pressure on a randomly chosen car. The probability distribution of X is as follows.a. Find P(1).b. Find P(More than 2).c. Find the probability that all four tires have low air pressure.d. Find the probability that no tires have low air pressure.e.
The National Health and Nutrition Survey reported that 30% of adults in the United States have hypertension (high blood pressure). A sample of 25 adults is studied.a. What is the probability that exactly 6 of them have hypertension?b. What is the probability that more than 8 have hypertension?c.
In a poll conducted by the General Social Survey, 81% of respondents said that their jobs were sometimes or always stressful. Ten workers are chosen at random.a. What is the probability that exactly 7 of them find their jobs stressful?b. What is the probability that more than 6 find their jobs
A certain large shipment comes with a guarantee that it contains no more than 15% defective items. If the proportion of items in the shipment is greater than 15%, the shipment may be returned. You draw a random sample of 10 items and test each one to determine whether it is defective.a. If in fact
Binomial probabilities are often hard to compute by hand, because the computation involves factorials and numbers raised to large powers. It can be shown through algebraic manipulation that if X is a random variable whose distribution is binomial with n trials and success probability p, thenIf we
The number of customers in line at a supermarket express checkout counter is a random variable with the following probability distribution.a. Find P(2).b. Find P(No more than 1).c. Find the probability that no one is in line.d. Find the probability that at least three people are in line.e. Compute
An insurance company offers a discount to homeowners who install smoke detectors in their homes. A company representative claims that 80% or more of policy holders have smoke detectors. You draw a random sample of 8 policy holders.a. If exactly 80% of the policy holders have smoke detectors(so the
The following table presents the probability distribution of the number of defects X in a randomly chosen printed circuit board.a. Find P(2).b. Find P(1 or more).c. Find the probability that at least two circuits are defective.d. Find the probability that no more than two circuits are defective.e.
Five teenagers are selected at random. Let X be the number of them who have sent text messages on their cell phones within the past 30 days. According to a study by the Nielsen Company, the probability distribution of X is as follows:a. Find P(2).b. Find P(More than 1).c. Find the probability that
The federal government has enacted maximum allowable standards for air pollutants such as ozone. Let X be the number of days per year that the level of air pollution exceeds the standard in a certain city. The probability distribution of X is given bya. Find P(1).b. Find P(3 or fewer).c. Find the
The General Social Survey asked 1676 people how many hours per day they were able to relax. The results are presented in the following table.Consider these 1676 people to be a population. Let X be the number of hours of relaxation for a person sampled at random from this population.a. Construct the
Let X represent the number of occupants in a randomly chosen car on a certain stretch of highway during morning commute hours. A survey of cars showed that the probability distribution of X is as follows.a. Find P(2).b. Find P(More than 3).c. Find the probability that a car has only one occupant.d.
The General Social Survey asked 827 people how many days they would wait to seek medical treatment if they were suffering pain that interfered with their ability to work. The results are presented in the following table.Consider these 827 people to be a population. Let X be the number of days for a
The following table presents the numbers of students enrolled in grades 1 through 8 in public schools in the United States.Consider these students to be a population. Let X be the grade of a student randomly chosen from this population.a. Construct the probability distribution of X.b. Find the
The World Cup soccer tournament has been held every four years since 1930, except for 1942 and 1946. The following table presents the number of goals scored by the winning team in each championship game.Consider these 20 games to be a population. Let X be the number of goals scored in a game
A multiple-choice question has five choices.If you get the question right, you gain one point, and if you get it wrong, you lose 1∕4 point. Assume you have no idea what the right answer is, so you pick one of the choices at random.a. What is the expected value of the number of points you get?b.
Another bet you can make in craps is that the sum of the dice will be 2 (also called ‘‘snake eyes’’). The probability that you win is 1∕36, and if you win, your profit is $30. If you lose, you lose $1. What is the expected value of your profit? Is it an expected gain or an expected loss?
An investor is considering a \($10,000\) investment in a start-up company. She estimates that she has probability 0.25 of a \($20,000\) loss, probability 0.20 of a \($10,000\) profit, probability 0.15 of a \($50,000\) profit, and probability 0.40 of breaking even (a profit of \($0).\) What is the
Refer to Exercise 55.Assume you can eliminate one of the five choices, and you choose one of the remaining four at random as your answer.a. What is the expected value of the number of points you get?b. If you don’t answer a question, you get 0 points. The test makers advise you to guess if you
An insurance company sells a one-year term life insurance policy to an 80-year-old woman. The woman pays a premium of \($1000.\) If she dies within one year, the company will pay \($20,000\) to her beneficiary. According to the U.S. Centers for Disease Control and Prevention, the probability that
A couple plans to have children until a girl is born, but they will have no more than three children. Assume that each child is equally likely to be a boy or a girl. Let Y be the number of boys they have.a. Find the probability distribution of Y.b. Find the mean μY .c. Find the standard deviation
The following table is a life table, reproduced from the chapter introduction. With an understanding of some basic concepts of probability, one can use the life table to compute the probability that a person of a given age will still be alive a given number of years from now. Life insurance
A quiz consists of three true–false questions and two multiple-choice questions with five choices each. How many different sets of answers are there?
In Example 5.4, what is the probability that the oldest child and the youngest child are of the same gender? Example 5.4 Computing probabilities A family has three children. Denoting a boy by B and a girl by G, we can denote the genders of these children from oldest to youngest. For example, GBG
A pollster will draw a simple random sample of voters from a large city to ask whether they support the construction of a new light rail line. Assume that there are one million voters in the city, and that 560,000 of them support this proposition.One voter is sampled at random.a. Identify the
In a certain city, 70% of high school students graduate. Of those who graduate, 40% attend college. Find the probability that a randomly selected high school student will attend college.
There were 30 students in last semester’s statistics class. Of these, 6 received a grade of A, and 12 received a grade of B. What is the probability that a randomly chosen student received a grade of A or B?
A college student is chosen at random. Event A is that the student is an only child, and event B is that the student has a brother. Are events A and B mutually exclusive?
A committee of eight people must choose a president, a vice president, and a secretary. In how many ways can this be done?
A penny and a nickel are tossed. Each is a fair coin, which means that heads and tails are equally likely.a. Construct a sample space containing equally likely outcomes. Each outcome should specify the results for both coins.b. Find the probability that one coin comes up heads and the other comes
State each of the following rules:a. General Addition Ruleb. Addition Rule for Mutually Exclusive Eventsc. Rule of Complementsd. General Multiplication Rulee. Multiplication Rule for Independent Events
Two dice are rolled. Each comes up with a number between 1 and 6.Let A be the event that the number on the first die is even, and let B be the event that the number on the second die is 6.a. Explain why events A and B are independent.b. Find P(A), P(B), and P(A and B).
In a statistics class of 45 students, 11 got a final grade of A, 22 got a final grade of B, and 8 got a final grade of C.a. What is the probability that a randomly chosen student got an A or a B?b. What is the probability that a randomly chosen student got an A, a B, or a C?
Explain why the General Addition Rule P (A or B) = P (A) + P (B) − P (A and B) may be used even when A and B are mutually exclusive events.
Refer to Exercise 3.Two of the committee members are Ellen and Jose. Assume the assignments are made at random,a. What is the probability that Jose is president and Ellen is vice president?b. What is the probability that either Ellen or Jose is president and the other is vice president?Exercise
There are 100,000 voters in a city. A pollster takes a simple random sample of 1000 of them and finds that 513 support a bond issue to support the public library, and 487 oppose it. Estimate the probability that a randomly chosen voter in this city supports the bond issue.
The following table presents the results of a survey in which 400 college students were asked whether they listen to music while studying.a. Find the probability that a randomly selected student does not listen to music while studying.b. Find the probability that a randomly selected student listens
A pollster plans to sample 1500 voters from a city in which there are 1 million voters.Can the sampled voters be treated as independent? Explain.
The General Addition Rule states that P (A or B) = P (A) + P (B) − __________________ .In Exercises 5–8, fill in each blank with the appropriate word or phrase.
Sometimes events are in the form ‘‘at least’’ a given number. For example, if a coin is tossed five times, an event could be getting at least two heads. What would be the complement of the event of getting at least two heads?
Eight college students have applied for internships at a local firm. Three of them will be selected for interviews. In how many ways can this be done?
Which of the following pairs of events are mutually exclusive?i. A: A randomly chosen student is 18 years old. B: The same student is 20 years old.ii. A: A randomly chosen student owns a red car. B: The same student owns a blue car.
Five hundred students attend a college basketball game. Fifty of them are chosen at random to receive a free T-shirt. Can the sampled students be treated as independent?Explain.
If events A and B are mutually exclusive, then P (A and B) = _________________ .In Exercises 5–8, fill in each blank with the appropriate word or phrase.
In practice, one must decide whether to treat two events as independent based on an understanding of the process that creates them. For example, in a manufacturing process that produces electronic circuit boards for calculators, assume that the probability that a board is defective is 0.01. You
In a group of 100 teenagers, 61 received their driver’s license on their first attempt on the driver’s certification exam and 18 received their driver’s license on their second attempt. What is the probability that a randomly selected teenager received their driver’s license on their first
An office has three smoke detectors. In case of fire, each detector has probability 0.9 of detecting it. If a fire occurs, what is the probability that at least one detector detects it?
Given an event A, the event that A does not occur is called the ___________________ of A.In Exercises 5–8, fill in each blank with the appropriate word or phrase.
Describe circumstances under which you would use a permutation.
If an operation can be performed in m ways, and a second operation can be performed in n ways, then the total number of ways to perform the sequence of two operations is _____________________ .In Exercises 7 and 8, fill in the blank with the appropriate word or phrase:
The collection of all possible outcomes of a probability experiment is called a _____________________ .In Exercises 5–8, fill in each blank with the appropriate word or phrase.
A certain neighborhood has 100 households. Forty-eight households have a dog as a pet. Of these, 32 also have a cat.Given that a household has a dog, what is the probability that it also has a cat?
A probability that is computed with the knowledge of additional information is called a _______________ probability.In Exercises 7–10, fill in each blank with the appropriate word or phrase.
The Rule of Complements states that P (Ac) = ___________________ .In Exercises 5–8, fill in each blank with the appropriate word or phrase.
Describe circumstances under which you would use a combination.
The number of permutations of 6 objects is ___________________ .In Exercises 7 and 8, fill in the blank with the appropriate word or phrase:
An outcome or collection of outcomes from a sample space is called an ____________________ .In Exercises 5–8, fill in each blank with the appropriate word or phrase.
The owner of a bookstore has determined that 80% of people who enter the store will buy a book. Of those who buy a book, 60% will pay with a credit card. Find the probability that a randomly selected person entering the store will buy a book and pay for it using a credit card.
The General Multiplication Rule states that P (A and B) = __________________ .In Exercises 7–10, fill in each blank with the appropriate word or phrase.
The General Addition Rule is used for probabilities of the form P (A or B).In Exercises 9–12, determine whether the statement is true or false. If the statement is false, rewrite it as a true statement.
In a permutation, order is not important.In Exercises 9 and 10, determine whether the statement is true or false. If the statement is false, rewrite it as a true statement.
When it comes to betting, the chance of winning or losing may be expressed as odds. If there are n equally likely outcomes and m of them result in a win, then the odds of winning are m:(n − m), read ‘‘m to n − m.’’ For example, suppose that a player rolls a die and wins if the number of
A college student is chosen at random. Event A is that the student is older than 21 years, and event B is that the student is taking a statistics class. Are events A and B mutually exclusive?
A person is selected at random from the population in Table 5.5.a. What is the probability that the person is a woman who is a high school graduate?b. What is the probability that the person is a high school graduate?c. What is the probability that the person is a woman, given that the person is a
Fill in the blank: The probability that a fair coin lands heads is 0.5. Therefore, we can be sure that if we toss a coin repeatedly, the proportion of times it lands heads will _______________________.i. approach 0.5 ii. be equal to 0.5 iii. be greater than 0.5 iv. be less than 0.5
In Example 5.4, what is the probability that the youngest child is a boy? Example 5.4 Computing probabilities A family has three children. Denoting a boy by B and a girl by G, we can denote the genders of these children from oldest to youngest. For example, GBG means the oldest child is a girl, the
When ordering a certain type of computer, there are three choices of hard drive, four choices for the amount of memory, two choices of video card, and three choices of monitor. In how many ways can a computer be ordered?
The following table is a life table, reproduced from the chapter introduction. With an understanding of some basic concepts of probability, one can use the life table to compute the probability that a person of a given age will still be alive a given number of years from now. Life insurance
Showing 6800 - 6900
of 7930
First
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
Last
Step by Step Answers
Get 50% OFF
Claim Now
