/*! 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 22 Another die is weighted in such ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Another die is weighted in such a way that each of 1 and 2 is three times as likely to come up as each of the other numbers. Find the probability distribution. What is the probability of rolling an even number?

Short Answer

Expert verified
The probability distribution of the weighted die is: P(1) = P(2) = \(\frac{3}{10}\), and P(3) = P(4) = P(5) = P(6) = \(\frac{1}{10}\). The probability of rolling an even number on this weighted die is \(\frac{1}{2}\), or 50%.

Step by step solution

01

Calculate the probability of each number

Let's represent the probability of rolling 1 or 2 as \(3x\), and the probability of rolling any other number as \(x\). The total probability of all six numbers should be equal to 1. We have a total of six numbers on the die: two numbers with a probability of \(3x\) and four with a probability of \(x\), so the total probability is \(2(3x) + 4(x)\), which should be equal to 1. So, we have: \(2(3x) + 4(x) = 1\) Now, we will solve for \(x\). \(6x + 4x = 1\) \(10x = 1\) \(x = \frac{1}{10}\) Now that we know the value of \(x\), we can find the probabilities of each number. Probabilities: - Rolling a 1 or 2: \(3x = 3\left(\frac{1}{10}\right) = \frac{3}{10}\) - Rolling a 3, 4, 5, or 6: \(x = \frac{1}{10}\) The probability distribution of this weighted die is: - P(1) = P(2) = \(\frac{3}{10}\) - P(3) = P(4) = P(5) = P(6) = \(\frac{1}{10}\)
02

Find the probability of rolling an even number

Now, we will find the probability of rolling an even number (2, 4, or 6). To find the probability, we add up the probabilities of rolling a 2, 4, or 6: P(even) = P(2) + P(4) + P(6) = \(\frac{3}{10} + \frac{1}{10} + \frac{1}{10} = \frac{5}{10} = \frac{1}{2}\) So, the probability of rolling an even number on this weighted die is \(\frac{1}{2}\), or 50%.

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.

Weighted Die
A weighted die is different from a fair die because it's designed to land on certain numbers more frequently than others. In this case, the numbers 1 and 2 are more likely to appear than the other numbers on the die.

A regular six-sided die, often called a fair die, gives equal chances for each number to show up, meaning each number has a probability of \( rac{1}{6}\). However, with a weighted die, probabilities are not equal for all outcomes.

For this weighted die, 1 and 2 appear three times as often as the other numbers. This causes an imbalance in the likelihood of rolling certain numbers compared to a fair die, resulting in a probability distribution that reflects these differences.
Probability Calculation
Calculating probabilities involves understanding the likelihood of different outcomes occurring. To calculate the probability for this weighted die, we first represent the probability of rolling a 1 or 2 as \(3x\), while rolling any other number as \(x\).

Given there are two numbers with likelihood \(3x\) and four numbers with likelihood \(x\), all probabilities add up to 1 (because one of the six possible outcomes must occur). The equation is:
  • \(2(3x) + 4(x) = 1\)
  • Solving gives \(10x = 1\), and thus \(x = \frac{1}{10}\)
With this value, individual probabilities can be determined:
  • Probability of rolling 1 or 2: \(3x = \frac{3}{10}\)
  • Probability of rolling 3, 4, 5, or 6: \(x = \frac{1}{10}\)
This calculation results in a clear representation of what to expect when rolling the die.
Even Number Probability
An even number on a die is any number that can be divided evenly by 2, such as 2, 4, and 6. Understanding the probability of rolling such numbers helps determine how likely those specific outcomes are on a weighted die.

To find this probability, we sum the probabilities of rolling each even number. Here, we use the probabilities calculated previously:
  • Probability of rolling a 2: \(\frac{3}{10}\)
  • Probability of rolling a 4: \(\frac{1}{10}\)
  • Probability of rolling a 6: \(\frac{1}{10}\)
Adding these, the probability of rolling an even number becomes:\[P(2 \text{ or } 4 \text{ or } 6) = \frac{3}{10} + \frac{1}{10} + \frac{1}{10} = \frac{5}{10} = \frac{1}{2}\]This equates to a 50% chance, providing insight into how likely rolling an even number is on the weighted die.

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

The Sad State Lottery requires you to select a sequence of three different numbers from 0 through 49 . (Order is important.) You are a winner if your sequence agrees with that in the drawing, and you are a booby prize winner if your selection of numbers is correct, but in the wrong order. What is the probability of being a winner? What is the probability of being a booby prize winner? What is the probability that you are either a winner or a booby prize winner?

\(\nabla\) Two distinguishable dice are rolled. Could there be two mutually exclusive events that both contain outcomes in which the numbers facing up add to 7 ?

The Sorry State Lottery requires you to select five different numbers from 0 through 49 . (Order is not important.) You are a Big Winner if the five numbers you select agree with those in the drawing, and you are a Small-Fry Winner if four of your five numbers agree with those in the drawing. What is the probability of being a Big Winner? What is the probability of being a Small-Fry Winner? What is the probability that you are either a Big Winner or a Small-Fry winner?

Weather Prediction There is a \(20 \%\) chance of snow today and a. \(20 \%\) chance of snow tomorrow. Assuming that the event that it snows today is independent of the event that it snows tomorrow, draw a tree diagram showing the probabilities of all outcomes. What is the probability that it will snow by the end of tomorrow?

An experiment is given together with an event. Find the (modeled) probability of each event, assuming that the coins and dice are distinguishable and fair, and that what is observed are the faces or numbers uppermost. Three coins are tossed; the result is at most one head.

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.