Probability Theory

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

Basic Concepts

Calculating Probability

How Do We Calculate Probability?

Probability tells us how likely an event is to happen, and it's always a number between 0 (impossible) and 1 (certain). If every outcome is equally likely, the probability of an event \(A\) is:

\[ P(A) = \frac{\text{Number of outcomes in } A}{\text{Total number of possible outcomes}} \]

Probability Rules

  • The probability of any event is between 0 and 1.
  • The sum of probabilities of all possible outcomes is 1.
  • The probability of the event "not \(A\)" is \(1 - P(A)\).

Using Probability in Everyday Life

We use probability to predict the weather, decide whether to take an umbrella, or figure out the odds of winning a board game!

Examples

  • The chance of rolling a 3 on a six-sided die is 1/6.

  • The probability of drawing a heart from a standard deck of cards is 13/52 = 1/4.

In a Nutshell

Probability measures how likely an event is to occur, using straightforward rules and simple math.