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91Ó°ÊÓ

Let \(F\) denote the event that a randomly selected registered voter in a certain city has signed a petition to recall the mayor. Also, let \(E\) denote the event that the randomly selected registered voter actually votes in the recall election. Describe the event \(E \cap F\) in words. If \(P(F)=.10\) and \(P(E \mid F)=.80\), determine \(P(E \cap F)\).

Short Answer

Expert verified
So, the probability of a randomly selected registered voter in the city both having signed a petition to recall the mayor and actually voting in the recall election (i.e., \(E \cap F\)) is 0.08 or 8%.

Step by step solution

01

Understand the Terminologies

The first step involves understanding the terms and their meanings. Here, \(F\) denotes the event where a selected voter has signed a recall petition, \(E\) represents the event where the selected voter actually votes in the election, and \(E \cap F\) here implies both these events happening simultaneously.
02

Interpret the Given Probabilities

The problem provides two probabilities - \(P(F) = 0.10\) which means there is a 10% likelihood a randomly selected voter has signed a recall petition, and \(P(E|F) = 0.80\), implying that given a voter has signed a recall petition, there is an 80% chance that they will vote in the election.
03

Apply Conditional Probability Rule

The conditional probability rule states that \(P(E \cap F) = P(E|F) \cdot P(F)\). Applying this rule here using the given probabilities, we substitute the given values to get \(P(E \cap F) = 0.80 \cdot 0.10 = 0.08 \).

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Key Concepts

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

Probability Theory
Probability theory is the branch of mathematics that deals with the analysis of random events. The foundation of probability is to measure the likelihood of a certain event occurring within a predefined set of possibilities. It is distinguished by its use of precise numerical values, known as probabilities, which range from 0 to 1 — where 0 indicates an impossibility, and 1 denotes certainty.

In the educational exercise, we are presented with the event of a voter signing a petition (\f\(F\f\)) and the event of a voter participating in the election (\f\(E\f\)). Probability theory allows us to compute the probability of these two events occurring together (\f\(E \fap F\f\)), which is essential for various applications, from risk assessment in finance and insurance to making informed decisions in everyday life.

Key Concepts in Probability

At the heart of probability theory are fundamental concepts such as:
  • Random experiments, where the outcome is not predictable in advance.
  • Sample space, which is the set of all possible outcomes of an experiment.
  • Events, which are subsets of the sample space that we are interested in.
  • Intersection of events (\f\(E \fap F\f\)), signifying the occurrence of multiple events simultaneously.
Statistics Education
Statistics education focuses on teaching methods for collecting, analyzing, interpreting, and presenting empirical data. A solid understanding of statistics is crucial for students of various disciplines, as it provides the tools to make sense of the data that permeate our world. In our example, statistics education would not just focus on how to calculate probabilities but also on understanding what these probabilities mean in a real-world context like voting behavior.

In the provided exercise, students learn how to calculate the joint probability of a voter signing a petition and voting in the election. Effective statistics education would incorporate discussion about why these probabilities matter, such as how they could be used by political analysts to forecast election turnout or by social scientists studying civic engagement.

Engaging with Real Data

The best statistics education often involves hands-on analysis of real data sets and practical application of statistical methods on topics that students find engaging or pertinent to their lives. By linking problems to real-world scenarios, students can better grasp abstract statistical concepts and see the value in learning them.
Event Intersection
In the context of probability theory, the term 'event intersection' refers to a situation where two different events occur at the same time. Mathematically, if we have two events, \f\(A\f\) and \f\(B\f\), their intersection (\f\(A \fap B\f\)) represents all the outcomes that \f\(A\f\) and \f\(B\f\) have in common.

Applying this to our scenario, \f\(E \fap F\f\) is the intersection between the event of a voter signing the petition (\f\(F\f\)) and the event of the voter voting in the election (\f\(E\f\)). To calculate the probability of the intersection of two events, we can use the principle of conditional probability. The probability of \f\(E\f\) given \f\(F\f\) is expressed as \f\(P(E|F)\f\), and by multiplying this with the probability of \f\(F\f\), we obtain the joint probability of both events occurring.

Understanding Through Context

Real-world examples help solidify the concept of event intersection. For instance, consider the chances of it raining while you have plans to go outside (\f\(R \fap O\f\)). This can show the practicality of understanding intersections as they relate to more than just academic exercises — they are a part of decision-making in daily life.

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Most popular questions from this chapter

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