/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 23 Poisson Approximation to Binomia... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Poisson Approximation to Binomial: Comparisons (a) For \(n=100, p=0.02\), and \(r=2\), compute \(P(r)\) using the formula for the binomial distribution and your calculator: $$ P(r)=C_{n, t} p^{r}(1-p)^{n-r} $$ (b) For \(n=100, p=0.02\), and \(r=2\), estimate \(P(r)\) using the Poisson approximation to the binomial. (c) Compare the results of parts (a) and (b). Does it appear that the Poisson distribution with \(\lambda=n p\) provides a good approximation for \(P(r=2) ?\) (d) Repeat parts (a) to \((c)\) for \(r=3\)

Short Answer

Expert verified
The Poisson approximation provides a good estimate for both \(r=2\) and \(r=3\) as the probabilities are very close to the binomial calculations.

Step by step solution

01

Calculate Binomial Probability for r=2

The formula for the binomial probability is \(P(r) = C_{n, r} p^r (1-p)^{n-r}\). We have \(n=100\), \(p=0.02\), and \(r=2\). First, compute the binomial coefficient:\[ C_{100, 2} = \frac{100!}{2!(100-2)!} = 4950\]Now, substitute the values into the formula:\[ P(2) = 4950 \cdot (0.02)^2 \cdot (0.98)^{98} \approx 0.2702 \]
02

Apply Poisson Approximation for r=2

The Poisson approximation is used when \(n\) is large and \(p\) is small. Here, \(\lambda = n \times p = 100 \times 0.02 = 2\). The Poisson probability is given by \(P(r) = \frac{e^{-\lambda} \lambda^r}{r!}\).For \(r=2\):\[ P(2) = \frac{e^{-2} \cdot 2^2}{2!} = \frac{4e^{-2}}{2} = 2e^{-2} \approx 0.2707 \]
03

Compare Results for r=2

For \(r=2\), the binomial probability is approximately 0.2702 and the Poisson approximation gives approximately 0.2707. The results are very close, suggesting that the Poisson distribution provides a good approximation for this case.
04

Calculate Binomial Probability for r=3

Using the binomial formula again for \(r=3\):The binomial coefficient is:\[ C_{100, 3} = \frac{100!}{3!(100-3)!} = 161700\]Substitute into the formula:\[ P(3) = 161700 \cdot (0.02)^3 \cdot (0.98)^{97} \approx 0.1804 \]
05

Apply Poisson Approximation for r=3

Using the same \(\lambda = 2\), the Poisson probability for \(r=3\) is given by:\[ P(3) = \frac{e^{-2} \cdot 2^3}{3!} = \frac{8e^{-2}}{6} = \frac{4}{3}e^{-2} \approx 0.1804 \]
06

Compare Results for r=3

For \(r=3\), both the binomial probability and the Poisson approximation result in approximately 0.1804. This confirms that the Poisson approximation is very accurate in this case as well.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Binomial Distribution
The binomial distribution is a crucial probability distribution used in statistics. It describes the odds of achieving a fixed number of successful outcomes in a set number of independent tests, or trials, of a binary process. A binary process is one where there are only two possible outcomes, often referred to as "success" and "failure."
For example, determining the probability of flipping a coin and getting heads 10 times in 20 flips can be modeled using a binomial distribution. The computation requires specifying two key parameters: the number of trials (denoted as \(n\)) and the probability of success in each trial (denoted as \(p\)).
Here's the formula for the binomial probability of exactly \(r\) successful outcomes:
\[ P(r) = C_{n, r} \cdot p^r \cdot (1-p)^{n-r} \]
This formula consists of:
  • \(C_{n, r}\): The binomial coefficient, representing the number of ways to choose \(r\) successes in \(n\) trials.
  • \(p^r\): The probability of obtaining \(r\) successes.
  • \((1-p)^{n-r}\): The probability of the remaining \(n-r\) trials being failures.
This distribution is particularly effective when dealing with large sample sizes and binary outcomes, such as pass/fail in exams or defective/non-defective product inspections.
Probability Calculations
Probability calculations are fundamental for assessing the likelihood of specific events occurring. They form the backbone of statistical inference and decision making. Understanding how to calculate probabilities using different distributions is essential in statistics education.
There are different probability distributions for different types of data and scenarios. For instance, the binomial distribution handles discrete events with two outcomes, while other distributions such as normal or Poisson are used for different data types and conditions.
Probability calculations often involve:
  • Using formulas and understanding their components (like binomial or Poisson formulas).
  • Determining conditions to apply certain distributions, such as large sample size for Poisson approximation.
  • Applying concepts of randomness and independence in probability events.
This exercise highlights probability calculations using both binomial and Poisson distributions to understand how close these estimates can be in certain circumstances.
Statistics Education
Statistics education provides learners with the tools to understand, analyze, and interpret data effectively. One essential component is learning about various probability distributions like the binomial and Poisson distributions.
This exercise provides a practical example of applying statistical concepts to solve real-world problems. By learning how to calculate probabilities, compare results, and understand approximations, students gain critical insight into how statistics can model the randomness and uncertainty we encounter.
Statistics education also involves:
  • Teaching the significance of selecting appropriate models and distributions for data analysis.
  • Developing a robust understanding of when to use approximations like the Poisson distribution, particularly when dealing with large \(n\) and small \(p\).
  • Fostering skills to interpret statistical outputs and use them in decision-making processes.
Through exercises like these, students get hands-on experience in applying theory to practice, which is fundamental in teaching effective statistics education.
Mathematics Problem Solving
Mathematics problem solving is crucial to understanding and applying statistical concepts in practical situations. This exercise illustrates how mathematics is used to approximate probabilities and compare them for accuracy.
Effective problem solving involves several steps:
  • Breaking down the problem: Identifying what is given and what needs to be found.
  • Selecting appropriate formulas and methods: Using both the binomial and Poisson distributions to solve and approximate probabilities as given in this exercise.
  • Performing calculations: Computing results for specific cases, such as \(r=2\) and \(r=3\).
  • Comparing and interpreting results: Evaluating the accuracy of approximations and understanding their limitations.
This approach develops mathematical reasoning and proficiency, which are vital skills in many fields, including science, engineering, and finance. By working through problems like these, students enhance their ability to think critically and solve complex mathematical challenges effectively.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

An archaeological excavation at Burnt Mesa Pueblo showed that about \(10 \%\) of the flaked stone objects were finished arrow points (Source: Bandelier Archaeological Excavation Project: Summer 1990 Excavations at Burnt Mesa Pueblo, edited by Kohler, Washington State University). How many flaked stone objects need to be found to be \(90 \%\) sure that at least one is a finished arrow point? (Hint: Use a calculator and note that \(P(r \geq 1) \geq 0.90\) is equivalent to \(1-P(0) \geq 0.90\), or \(P(0) \leq 0.10 .)\)

The Honolulu Advertiser stated that in Honolulu there was an average of 661 burglaries per 100,000 households in a given year. In the Kohola Drive neighborhood there are 316 homes. Let \(r=\) number of these homes that will be burglarized in a year. (a) Explain why the Poisson approximation to the binomial would be a good choice for the random variable \(r .\) What is \(n\) ? What is \(p ?\) What is \(\lambda\) to the nearest tenth? (b) What is the probability that there will be no burglaries this year in the Kohola Drive neighborhood? (c) What is the probability that there will be no more than one burglary in the Kohola Drive neighborhood? (d) What is the probability that there will be two or more burglaries in the Kohola Drive neighborhood?

What does the expected value of a binomial distribution with \(n\) trials tell you?

Norb and Gary are entered in a local golf tournament. Both have played the local course many times. Their scores are random variables with the following means and standard deviations. $$ \text { Norb, } x_{1}: \mu_{1}=115 ; \sigma_{1}=12 \quad \text { Gary, } x_{2}: \mu_{2}=100 ; \sigma_{2}=8 $$ In the tournament, Norb and Gary are not playing together, and we will assume their scores vary independently of each other. (a) The difference between their scores is \(W=x_{1}-x_{2} .\) Compute the mean, variance, and standard deviation for the random variable \(W\). (b) The average of their scores is \(W=0.5 x_{1}+0.5 x_{2}\). Compute the mean, variance, and standard deviation for the random variable W (c) The tournament rules have a special handicap system for each player. For Norb, the handicap formula is \(L=0.8 x_{1}-2 .\) Compute the mean, variance, and standard deviation for the random variable \(L .\) (d) For Gary, the handicap formula is \(L=0.95 x_{2}-5 .\) Compute the mean, variance, and standard deviation for the random variable \(L\).

Harper's Index reported that the number of (Orange County, California) convicted drunk drivers whose sentence included a tour of the morgue was 569 , of which only 1 became a repeat offender. (a) Suppose that of 1000 newly convicted drunk drivers, all were required to take a tour of the morgue. Let us assume that the probability of a repeat offender is still \(p=1 / 569 .\) Explain why the Poisson approximation to the binomial would be a good choice for \(r=\) number of repeat offenders out of 1000 convicted drunk drivers who toured the morgue. What is \(\lambda\) to the nearest tenth? (b) What is the probability that \(r=0\) ? (c) What is the probability that \(r>1\) ? (d) What is the probability that \(r>2\) ? (e) What is the probability that \(r>3\) ?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.