Probability

Two events and are mutually exclusive if . Events that are mutually exclusive can have their probabilities added.

Set notation can be used to describe probabilities:

  • is the union of and , meaning when either or (inclusive) happens.
  • is the intersection of and , meaning when both and happen.
  • is the complement of , meaning when everything that is not happens.

A Venn diagram can be used to find the formula relating the probabilities of the union and intersection:

Events and are independent if . Another condition is given by:

because .

is the probability of happening given that has happened (the probability of given ). We can use the formula:

Rearranging, we get:

Interactive Graph
Table Of Contents
Probability