Probability Theory

Probability Theory explores the mathematical framework for quantifying uncertainty and making informed decisions based on random events.

Basic Concepts

Random Experiments and Events

What Are Random Experiments?

A random experiment is any process that can be repeated and has uncertain outcomes. Even if you do the same thing multiple times, you might get different results each time. That's the heart of probability!

Types of Events

An event is a set of outcomes from a random experiment. Events can be simple (like flipping a coin and getting heads) or compound (like rolling a dice and getting an even number).

Sample Space

The sample space is the set of all possible outcomes. For instance, when rolling a six-sided die, the sample space is \({1, 2, 3, 4, 5, 6}\).

Why Does This Matter?

Understanding random experiments and events is the foundation of probability. It helps you organize possible outcomes and figure out what you might expect to happen.

Common Symbols

  • \(\Omega\): Sample space
  • \(A\): An event
  • \(P(A)\): Probability of event \(A\)

Examples

  • Tossing a coin (outcomes: heads or tails)

  • Drawing a card from a shuffled deck (outcomes: Ace, 2, ..., King of any suit)

In a Nutshell

Random experiments are processes with unpredictable outcomes, and events are sets of those outcomes.

Key Terms

Random Experiment
An action or process that leads to one of several possible outcomes, where the outcome cannot be predicted with certainty.
Sample Space
The set of all possible outcomes of a random experiment.
Event
A collection of outcomes from the sample space.