A series of free Statistics Lectures with lessons, examples & solutions in videos.
This is the eighth page of the series of free video lessons, “Statistics Lectures”. These lectures discuss probability.
Related Pages
6: Skewness, Normal Distribution, Empirical Rule
7: Z-Scores
9: Permutations & Combinations
10: Discrete & Continuous Random Variable
Jump to Table of Contents
Probability is a measure of the likelihood of an event.
A sample space is a collection of all possible outcomes.
An event with a probability of 0 is impossible (it will never happen).
An event with a probability of 1 is certain (it will always occur).
Two events are mutually exclusive if they cannot occur at the same time.
Addition rule for mutually exclusive events:
P(A or B) = P(A) + P(B)
Two events are independent if they do not affect one another.
Multiplication Rule for independent events:
P(A and B) = P(A) × P(B)
General Multiplication Rule for Dependent or Conditional Event:
P(A and B) = P(A) × P(B | A)
Check out our most popular games!
Fraction Concoction Game:
Master fractions in the lab: mix, add, and subtract beakers to create the perfect concoction!
Fact Family Game:
Complete fact families and master the link between addition & subtraction and multiplication & division.
Number Bond Garden:
Clear the board by matching number pairs that sum to ten in this garden-themed mental math puzzle.
Online Addition Subtraction Game:
Practice your addition and subtraction skills to help the penguin find its mummy.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.