A series of free Statistics Lectures with examples & solutions in videos.

These lectures discuss probability.

This is the eighth page of the series of free video lessons, "Statistics Lectures".
### Statistics - Lecture 21

The Basics of Probability

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).

### Statistics - Lecture 22

Addition Rule (Probability "or")

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)### Statistics - Lecture 23

Multiplication Rule (Probability "and")

Two events are independent if they do not affect one another.

Multiplication Rule for independent events:

P(A and B) = P(A) x P(B)

General Multiplication Rule for Dependent or Conditional Event:

P(A and B) = P(A) x P(B|A)

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

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) x P(B)

General Multiplication Rule for Dependent or Conditional Event:

P(A and B) = P(A) x P(B|A)

Rotate to landscape screen format on a mobile phone or small tablet to use the **Mathway** widget, a free math problem solver that **answers your questions with step-by-step explanations**.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

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