Elementary Statistics: A Step By Step Approach
Elementary Statistics: A Step By Step Approach
10th Edition
ISBN: 9781259755330
Author: Allan G. Bluman
Publisher: McGraw-Hill Education
bartleby

Concept explainers

bartleby

Videos

Textbook Question
Chapter 5.4, Problem 1AC

Rockets and Targets

During the latter days of World War II, the Germans developed flying rocket bombs. These bombs were used to attack London. Allied military intelligence didn’t know whether these bombs were fired at random or had a sophisticated aiming device. To determine the answer, they used the Poisson distribution.

To assess the accuracy of these bombs, London was divided into 576 square regions. Each region was 1 4 square kilometer in area. They then compared the number of actual hits with the theoretical number of hits by using the Poisson distribution. If the values in both distributions were close, then they would conclude that the rockets were fired at random. The actual distribution is as follows:

Hits 0 1 3 4 5 Regions 229 211 93 35 7 1

Using the Poisson distribution, find the theoretical values for each number of hits. In this case, the number of bombs was 535, and the number of regions was 576. So

λ = 535 576 0.929

For 3 hits,

P ( X ) = ( 2.7183 ) 0.929 ( 0.929 ) 3 3

Hence, the number of hits is (0.0528)(576) = 30.4128.

Complete the table for the other number of hits.

Hints 0 1 2 3 4 Regions 30 .4

2. Write a brief statement comparing the two distributions.

3. Based on your answer to question 2, can you conclude that the rockets were fired at random?

1.

Expert Solution
Check Mark
To determine

The theoretical values for the number of hits using Poisson distribution and to complete the given table.

Answer to Problem 1AC

The theoretical value for 0 hit is 227.5 regions.

The theoretical value for 1 hit is 211 regions.

The theoretical value for 2 hits is 97.9 regions.

The theoretical value for 3 hits is 30.4 regions.

The theoretical value for 4 hits is 7.1 regions.

The theoretical value for 5 hits is 1.3 regions.

The completed table is given below:

Hits 0 1 2 3 4 5
Regions 227.5 211 97.9 30.4 7.1 1.3

Explanation of Solution

Given info:

The table shows the number of bombs for 576 regions.

Hits 0 1 2 3 4 5
Regions 229 211 93 35 7 1

The theoretical values for the number of hits are:

Hits 0 1 2 3 4 5
Regions 30.4

The mean number of hits is given to be 0.929.

Calculation:

For 0 hits, the theoretical value is,

P(0)=eλλXX!=(2.7183)0.929(0.929)00!=0.394

Thus, 227.5(=0.395×576) regions had no hits.

For 1 hit, the theoretical value is,

P(1)=eλλXX!=(2.7183)0.929(0.929)11!=0.394(0.929)=0.366

Thus, 211(=0.366×576) regions had 1 hit.

For 2 hits, the theoretical value is,

P(2)=eλλXX!=(2.7183)0.929(0.929)22!=0.394(0.863)2=0.342

         =0.17

Thus, 97.9(=0.17×576) regions had 2 hits.

For 3 hits, the theoretical value is,

P(3)=eλλXX!=(2.7183)0.929(0.929)33!=0.394(0.802)6=0.3166

         =0.053

Thus, 30.4(=0.0527×576) regions had 3 hits.

For 4 hits, the theoretical value is,

P(4)=eλλXX!=(2.7183)0.929(0.929)44!=0.394(0.745)24=0.29424

         =0.0123

Thus, 7.1(=0.0123×576) regions had 4 hits.

For 5 hits, the theoretical value is,

P(5)=eλλXX!=(2.7183)0.929(0.929)55!=0.394(0.692)120=0.273120

         =0.0023

Thus, 1.3(=0.0023×576) regions had 5 hits.

2.

Expert Solution
Check Mark
To determine

To write: A brief statement comparing the two distributions.

Explanation of Solution

Statement:

The actual values are very close to the theoretical values. Hence Poisson distribution fits the data well.

3.

To conclude: Whether the rockets are fired at random.

Conclusion:

Yes, the rockets were fired at random because the theoretical values and the actual values are closer.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Chapter 5 Solutions

Elementary Statistics: A Step By Step Approach

Ch. 5.1 - For Exercises 7 through 12, determine whether the...Ch. 5.1 - For Exercises 7 through 12, determine whether the...Ch. 5.1 - For Exercises 7 through 12, determine whether the...Ch. 5.1 - For Exercises 13 through 18, state whether the...Ch. 5.1 - For Exercises 13 through 18, state whether the...Ch. 5.1 - For Exercises 13 through 18, state whether the...Ch. 5.1 - For Exercises 13 through 18, state whether the...Ch. 5.1 - For Exercises 13 through 18, state whether the...Ch. 5.1 - For Exercises 13 through 18, state whether the...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - For Exercises 19 through 26, construct a...Ch. 5.1 - Triangular Numbers The first six triangular...Ch. 5.1 - Child Play in Day Care In a popular day care...Ch. 5.1 - Goals in Hockey The probability that a hockey team...Ch. 5.1 - Mathematics Tutoring Center At a drop-in...Ch. 5.1 - For Exercises 31 through 36, write the...Ch. 5.1 - For Exercises 31 through 36, write the...Ch. 5.1 - For Exercises 31 through 36, write the...Ch. 5.1 - For Exercises 31 through 36, write the...Ch. 5.1 - For Exercises 31 through 36, write the...Ch. 5.1 - For Exercises 31 through 36, write the...Ch. 5.1 - Computer Games The probability that a child plays...Ch. 5.2 - Radiation Exposure On March 28, 1979, the nuclear...Ch. 5.2 - Coffee with Meals A researcher wishes to determine...Ch. 5.2 - Suit Sales The number of suits sold per day at a...Ch. 5.2 - Daily Newspapers A survey was taken of the number...Ch. 5.2 - Trivia Quiz The probabilities that a player will...Ch. 5.2 - New Homes A contractor has four new home plans....Ch. 5.2 - Traffic Accidents The county highway department...Ch. 5.2 - Fitness Machine A fitness center bought a new...Ch. 5.2 - Benfords Law The leading digits in actual data,...Ch. 5.2 - Automobiles A survey shows the probability of the...Ch. 5.2 - Pizza Deliveries A pizza shop owner determines the...Ch. 5.2 - Grab Bags A convenience store has made up 20 grab...Ch. 5.2 - Job Bids A landscape contractor bids on jobs where...Ch. 5.2 - Rolling Dice If a person rolls doubles when she...Ch. 5.2 - Dice Game A person pays 2 to play a certain game...Ch. 5.2 - Lottery Prizes A lottery offers one 1000 prize,...Ch. 5.2 - Winning the Lottery For a daily lottery, a person...Ch. 5.2 - Life Insurance A 35-year-old woman purchases a...Ch. 5.2 - Roulette A roulette wheel has 38 numbers, 1...Ch. 5.2 - Rolling Dice Construct a probability distribution...Ch. 5.2 - Rolling a Die When one die is rolled, the expected...Ch. 5.2 - The formula for finding the variance for a...Ch. 5.2 - Complete the following probability distribution if...Ch. 5.2 - Probability Distribution A bag contains five balls...Ch. 5.3 - Unsanitary Restaurants Health officials routinely...Ch. 5.3 - Which of the following are binomial experiments or...Ch. 5.3 - Which of the following are binomial experiments or...Ch. 5.3 - Compute the probability of X successes, using...Ch. 5.3 - Compute the probability of X successes, using...Ch. 5.3 - Compute the probability of X successes, using the...Ch. 5.3 - Compute the probability of X successes, using the...Ch. 5.3 - Belief in UFOs A survey found that 10% of...Ch. 5.3 - Multiple-Choice Exam A student takes a...Ch. 5.3 - High Blood Pressure Twenty percent of Americans...Ch. 5.3 - High School Dropouts Approximately 10.3% of...Ch. 5.3 - Advertising Three out of four people think most...Ch. 5.3 - Language Spoken at Home by the U.S. Population In...Ch. 5.3 - Prison Inmates Forty percent of prison inmates...Ch. 5.3 - Destination Weddings Twenty-six percent of couples...Ch. 5.3 - People Who Have Some College Education Fifty-three...Ch. 5.3 - Guidance Missile System A missile guidance system...Ch. 5.3 - Find the mean, variance, and standard deviation...Ch. 5.3 - Find the mean, variance, and standard deviation...Ch. 5.3 - Airline Accidents Twenty-five percent of...Ch. 5.3 - Tossing Coins Find the mean, variance, and...Ch. 5.3 - American and Foreign-Born Citizens In 2014 the...Ch. 5.3 - Federal Government Employee E-mail Use It has been...Ch. 5.3 - Watching Fireworks A survey found that 21% of...Ch. 5.3 - Alternate Sources of Fuel Eighty-five percent of...Ch. 5.3 - Survey on Bathing Pets A survey found that 25% of...Ch. 5.3 - Survey on Answering Machine Ownership In a survey,...Ch. 5.3 - Poverty and the Federal Government One out of...Ch. 5.3 - Internet Purchases Thirty-two percent of adult...Ch. 5.3 - Prob. 29ECh. 5.3 - Job Elimination In a recent year, 13% of...Ch. 5.3 - Survey of High School Seniors Of graduating high...Ch. 5.3 - Is this a binomial distribution? Explain.Ch. 5.3 - Children in a Family The graph shown here...Ch. 5.3 - Construct a binomial distribution graph for the...Ch. 5.3 - Show that the mean for a binomial random variable...Ch. 5.4 - Rockets and Targets During the latter days of...Ch. 5.4 - Use the multinomial formula and find the...Ch. 5.4 - Use the multinomial formula and find the...Ch. 5.4 - MMs Color Distribution According to the...Ch. 5.4 - Truck Inspection Violations The probabilities are...Ch. 5.4 - Prob. 5ECh. 5.4 - Mendels Theory According to Mendels theory, if...Ch. 5.4 - Find each probability P(X; ), using Table C in...Ch. 5.4 - Find each probability P(X; ) using Table C in...Ch. 5.4 - Study of Robberies A recent study of robberies for...Ch. 5.4 - Misprints on Manuscript Pages In a 400-page...Ch. 5.4 - Colors of Flowers A nursery provides red impatiens...Ch. 5.4 - Mail Ordering A mail-order company receives an...Ch. 5.4 - Company Mailing Of a companys mailings 1.5% are...Ch. 5.4 - Emission Inspection Failures If 3% of all cars...Ch. 5.4 - Phone Inquiries The average number of phone...Ch. 5.4 - Defective Calculators In a batch of 2000...Ch. 5.4 - School Newspaper Staff A school newspaper staff is...Ch. 5.4 - Job Applicants Twelve people apply for a teaching...Ch. 5.4 - Prob. 19ECh. 5.4 - Defective Computer Keyboards A shipment of 24...Ch. 5.4 - Defective Electronics A shipment of 24 smartphones...Ch. 5.4 - Job Applications Ten people apply for a job at...Ch. 5.4 - Auto Repair Insurance A person calls people to ask...Ch. 5.4 - Prob. 24ECh. 5.4 - Shooting an Arrow Mark shoots arrows at a target...Ch. 5.4 - Amusement Park Game At an amusement park...Ch. 5.4 - Prob. 27ECCh. 5.4 - Prob. 28ECCh. 5.4 - Drawing Cards Cards are drawn at random from a...Ch. 5.4 - Prob. 30ECCh. 5.4 - Prob. 31ECCh. 5.4 - Lessons Outside of School About 2 out of every 3...Ch. 5.4 - Prob. 33ECCh. 5.4 - Work versus Conscience One worker in four in...Ch. 5 - For Exercises 1 through 3, determine whether the...Ch. 5 - For Exercises 1 through 3, determine whether the...Ch. 5 - Prob. 5.1.3RECh. 5 - Prob. 5.1.4RECh. 5 - Credit Cards A large retail company encourages its...Ch. 5 - Prob. 5.1.6RECh. 5 - Shoe Purchases At Shoe World, the manager finds...Ch. 5 - Prob. 5.2.8RECh. 5 - Arrivals at an Airport At a small rural airport,...Ch. 5 - Cans of Paint Purchased During a recent paint sale...Ch. 5 - Phone Customers A phone service center keeps track...Ch. 5 - Outdoor Regatta A producer plans an outdoor...Ch. 5 - Card Game A game is set up as follows: All the...Ch. 5 - Card Game Using Exercise 13, how much should be...Ch. 5 - Let x be a binomial random variable with n = 12...Ch. 5 - Internet Access via Cell Phone In a retirement...Ch. 5 - Self-Driving Automobile Fifty-eight percent of...Ch. 5 - Prob. 5.3.18RECh. 5 - U.S. Police Chiefs and the Death Penalty The...Ch. 5 - Prob. 5.3.20RECh. 5 - Pizza for Breakfast Three out of four American...Ch. 5 - Prob. 5.3.22RECh. 5 - Prob. 5.4.23RECh. 5 - Prob. 5.4.24RECh. 5 - Accounting Errors The probability that an...Ch. 5 - Prob. 5.4.26RECh. 5 - Prob. 5.4.27RECh. 5 - Boating Accidents The number of boating accidents...Ch. 5 - Prob. 5.4.29RECh. 5 - Prob. 5.4.30RECh. 5 - Items Donated to a Food Bank At a food bank a case...Ch. 5 - Prob. 5.4.32RECh. 5 - Prob. 5.4.33RECh. 5 - Determine whether each statement is true or false....Ch. 5 - Determine whether each statement is true or false....Ch. 5 - Determine whether each statement is true or false....Ch. 5 - Determine whether each statement is true or false....Ch. 5 - Complete these statements with the best answer. 5....Ch. 5 - Complete these statements with the best answer. 6....Ch. 5 - Complete these statements with the best answer. 7....Ch. 5 - Select the best answer. 8. What is the sum of the...Ch. 5 - Select the best answer. 9. How many outcomes are...Ch. 5 - Select the best answer. 10. The number of trials...Ch. 5 - Prob. 11CQCh. 5 - Prob. 12CQCh. 5 - For exercises 11 through 14, determine if the...Ch. 5 - For exercises 11 through 14, determine if the...Ch. 5 - Prob. 15CQCh. 5 - Prob. 16CQCh. 5 - Prob. 17CQCh. 5 - Calls for a Crisis Hot Line The number of calls...Ch. 5 - Selecting a Card There are 6 playing cards placed...Ch. 5 - Prob. 20CQCh. 5 - Carpooling If 40% of all commuters ride to work in...Ch. 5 - Employed Women If 60% of all women are employed...Ch. 5 - Prob. 23CQCh. 5 - Meeting Attendance A history class has 75 members....Ch. 5 - Prob. 25CQCh. 5 - Quality Control Check Before a television set...Ch. 5 - Bowling Team Uniforms Among the teams in a bowling...Ch. 5 - Elm Trees If 8% of the population of trees are elm...Ch. 5 - Sports Score Hot Line Calls Sports Scores Hot Line...Ch. 5 - Color of Raincoats There are 48 raincoats for sale...Ch. 5 - Youth Group Officers A youth group has 8 boys and...Ch. 5 - Blood Types About 4% of the citizens of the United...Ch. 5 - Alcohol Abstainers About 35% of Americans abstain...Ch. 5 - Prob. 1CTCCh. 5 - Prob. 2CTCCh. 5 - Prob. 3CTCCh. 5 - Prob. 4CTCCh. 5 - Prob. 5CTC
Knowledge Booster
Statistics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Recommended textbooks for you
  • Holt Mcdougal Larson Pre-algebra: Student Edition...
    Algebra
    ISBN:9780547587776
    Author:HOLT MCDOUGAL
    Publisher:HOLT MCDOUGAL
    College Algebra (MindTap Course List)
    Algebra
    ISBN:9781305652231
    Author:R. David Gustafson, Jeff Hughes
    Publisher:Cengage Learning
  • Holt Mcdougal Larson Pre-algebra: Student Edition...
    Algebra
    ISBN:9780547587776
    Author:HOLT MCDOUGAL
    Publisher:HOLT MCDOUGAL
    College Algebra (MindTap Course List)
    Algebra
    ISBN:9781305652231
    Author:R. David Gustafson, Jeff Hughes
    Publisher:Cengage Learning
    Sampling Methods and Bias with Surveys: Crash Course Statistics #10; Author: CrashCourse;https://www.youtube.com/watch?v=Rf-fIpB4D50;License: Standard YouTube License, CC-BY
    Statistics: Sampling Methods; Author: Mathispower4u;https://www.youtube.com/watch?v=s6ApdTvgvOs;License: Standard YouTube License, CC-BY