/*! 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 14 Stoplight On her drive to work e... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Stoplight On her drive to work every day, Ilana passes through an intersection with a traffic light. The light has probability \(1 / 3\) of being green when she gets to the intersection. Explain how you would use each chance device to simulate whether the light is red or green on a given day. (a) A six-sided die (b) Table D of random digits (c) A calculator or computer's random integer generator

Short Answer

Expert verified
Divide six die faces, assign digits, or use random integers to simulate red/green light outcomes in a 1:3 ratio.

Step by step solution

01

Using a six-sided die

To simulate whether the light is red or green using a six-sided die, divide the face outcomes into two groups to match the probability of the light being green (1/3). Since 1/3 of 6 is approximately 2, assign two of the six sides to be green and the remaining four sides to be red. For example, roll the die: if it shows 1 or 2, the light is green; if it shows 3, 4, 5, or 6, the light is red.
02

Using Table D of random digits

To use a table of random digits, consider choosing digits 0 through 8. Since 1 out of 3 corresponds to approximately 3 choices out of 9 (rounding down to ensure fairness and avoid bias), you can assign three digits to green and the remaining six to red. For example, select a digit from the table: if it is 0, 1, or 2, the light is green; for any digit 3 through 8, the light is red. If you encounter a 9, skip it and choose the next number.
03

Using a calculator or computer's random integer generator

Use the random integer generator to produce numbers from 1 to 3. Assign one of these numbers (e.g., 1) to represent green and the other numbers (2 and 3) to represent red. Generate a random integer: if the number is 1, the light is green; if it is 2 or 3, the light is red.

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.

Random Number Generators
Random number generators are essential tools in probability simulations, helping to create outcomes that mimic real-life random events. They can be physical or computational. In classical settings, random number generators include devices like dice or shuffled decks, which physically represent randomness.
Today, we predominantly use computer-based random number generators for more complex simulations. They leverage algorithms to produce sequences of numbers that replicate the unpredictability of truly random sequences. These sequences are called pseudorandom numbers, and while they appear random, they are generated by a deterministic process based on an initial seed value.
Common tools used to generate random numbers include:
  • Computational algorithms such as the Linear Congruential Generator (LCG) or Mersenne Twister
  • Hardware-based atmospheric noise generators for applications requiring true randomness
In the context of the exercise, a simple random integer generator was used to divide probabilities into discrete outcomes, such as simulating the color of a traffic light.
Probability Distributions
Probability distributions provide a mathematical framework to describe how probabilities are distributed over the potential outcomes of a random experiment. They are fundamental in predicting the likelihood of occurrences in uncertain situations.
The type of distribution depends on the kind of random variable. For example, the uniform distribution describes a scenario where each outcome is equally likely. The exercise employs uniform distribution to simulate the chance of the light being either red or green by allocating probabilities to specific outcomes using devices like dice and tables of random digits.
Here’s how the concept works for our stoplight example:
  • Green is assigned a probability of 1/3.
  • Red is assigned a probability of 2/3.
  • Devices such as dice are divided so that outcomes align with these probabilities.
This division ensures that each event outcome aligns with the planned probabilities, such as a six-sided die where two faces indicate green and four indicate red.
Statistical Modeling
Statistical modeling involves creating mathematical representations of real-world processes, incorporating randomness and uncertainty to predict future outcomes. It is central to a vast array of disciplines, enabling predictions from stock prices to weather conditions.
In this exercise, statistical modeling is simplified into simulating the probability of a traffic light's color. This requires understanding both the probabilities and the method of simulation. Each device, whether it's a physical die or a random number table, acts as a model simulating the light's behavior based on set probabilities.
Key aspects of effective statistical modeling:
  • Accurate representation of the underlying probability distribution, like the 1/3 probability of a green light
  • Choice of simulation tools that reflect real-world randomness efficiently, such as using dice or computer algorithms
This process ensures that our model remains a valid predictor of real-life events, allowing users to make informed decisions based on the simulated outcomes.

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

Ten percent of U.S. households contain 5 or more people. You want to simulate choosing a household at random and recording "Yes" if it contains 5 or more people. Which of these are correct assignments of digits for this simulation? (a) Odd \(=\) Yes; Even \(=\) No (b) \(0=\) Yes; \(1-9=\) No (c) \(0-5=\) Yes; \(6-9=\) No (d) \(0-4=\) Yes; \(5-9=\) No (e) None of these

Testing the test Are false positives too common in some medical tests? Researchers conducted an experiment involving 250 patients with a medical condition and 750 other patients who did not have the medical condition. The medical technicians who were reading the test results were unaware that they were subjects in an experiment. (a) Technicians correctly identified 240 of the 250 patients with the condition. They also identified 50 of the healthy patients as having the condition. What were the false positive and false negative rates for the test? (b) Given that a patient got a positive test result, what is the probability that the patient actually had the medical condition? Show your work.

Free downloads? Illegal music downloading has become a big problem: \(29 \%\) of Internet users download music files, and \(67 \%\) of downloaders say they don't care if the music is copyrighted. \({ }^{17}\) What percent of Internet users download music and don't care if it's copyrighted? Write the information given in terms of probabilities, and use the general multiplication rule.

Airport security The Transportation Security Administration (TSA) is responsible for airport safety. On some flights, TSA officers randomly select passengers for an extra security check prior to boarding. One such flight had 76 passengers -12 in first class and 64 in coach class. Some passengers were surprised when none of the 10 passengers chosen for screening were seated in first class. We can use a simulation to see if this result is likely to happen by chance. (a) State the question of interest using the language of probability. (b) How would you use random digits to imitate one repetition of the process? What variable would you measure? (c) Use the line of random digits below to perform one repetition. Copy these digits onto your paper. Mark directly on or above them to show how you determined the outcomes of the chance process. \(\begin{array}{lllll}71487 & 09984 & 29077 & 14863 & 61683 & 47052 & 62224 & 51025\end{array}\) (d) In 100 repetitions of the simulation, there were 15 times when none of the 10 passengers chosen was seated in first class. What conclusion would you draw?

Roulette An American roulette wheel has 38 slots with numbers 1 through \(36,0,\) and \(00,\) as shown in the figure. Of the numbered slots, 18 are red, 18 are black, and 2 - the 0 and 00 - are green. When the wheel is spun, a metal ball is dropped onto the middle of the wheel. If the wheel is balanced, the ball is equally likely to settle in any of the numbered slots. Imagine spinning a fair wheel once. Define events \(B\) : ball lands in a black slot, and \(E\) : ball lands in an even-numbered slot. (Treat 0 and 00 as even numbers. \()\) (a) Make a two-way table that displays the sample space in terms of events \(B\) and \(E\). (b) Find \(P(B)\) and \(P(E)\). (c) Describe the event \({ }^{\alpha} B\) and \(E^{\prime \prime}\) in words. Then find \(P(B\) and \(E)\) (d) Explain why \(P(B\) or \(E) \neq P(B)+P(E) .\) Then use the general addition rule to compute \(P(B\) or \(\bar{E})\)

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.