AP®︎ Statistics (pre-2026) Unit 4: Notes & Study Guide

Prepare for your quiz, test, or the AP exam with a comprehensive review on Unit 4 of AP Statistics (pre-2026) – Probability, Random Variables, and Probability Distributions.

Exam weight: 10-20%
12 Topics

Unit 4: Probability, Random Variables, and Probability Distributions

The rules of probability and how random variables and their distributions set up everything in inference.

Begin with Topic 4.1: Introducing Statistics: R...

To review Unit 4, go through each of the 12 topics below.

Everything you actually need to know for your Unit 4 test, pulled directly from the AP® Statistics (pre-2026) curriculum.

Topic 4.1
~6 min
Review
Introducing Statistics: Random and Non-Random Patterns?
Introducing Statistics: Random and Non-Random Patterns?
  • Random Variation and Non-Random Patterns
  • Patterns in Data and the Questions They Suggest
  • Why Random Patterns Can Look Non-Random
Review
Topic 4.2
~6 min
Review
Estimating Probabilities Using Simulation
Estimating Probabilities Using Simulation
  • Random Processes, Outcomes, and Events
  • What a Simulation Is and Why It Works
  • How to Design and Run a Simulation
Review
Topic 4.3
~7 min
Review
Introduction to Probability
Introduction to Probability
  • Probability as Long-Run Relative Frequency
  • Sample Space and Events
  • The Basic Probability Rules
Review
Topic 4.4
~5 min
Review
Mutually Exclusive Events
Mutually Exclusive Events
  • What the Intersection of Two Events Means
  • Mutually Exclusive Events
  • The Addition Rule and When to Use It
Review
Topic 4.5
~6 min
Review
Conditional Probability
Conditional Probability
  • Conditional Probability Explained
  • The Multiplication Rule and Joint Probability
  • Finding Conditional Probability from Different Representations
Review
Topic 4.6
~6 min
Review
Independent Events and Unions of Events
Independent Events and Unions of Events
  • What Independent Events Are
  • The Multiplication Rule for Independent Events
  • What a Union Is
Review
Topic 4.7
~6 min
Review
Introduction to Random Variables and Probability Distributions
Introduction to Random Variables and Probability Distributions
  • What a Random Variable Is
  • Representing a Discrete Probability Distribution
  • Finding Probabilities from a Distribution
Review
Topic 4.8
~6 min
Review
Mean and Standard Deviation of Random Variables
Mean and Standard Deviation of Random Variables
  • Parameters of a Discrete Random Variable
  • The Mean or Expected Value \( \mu_X \)
  • Variance and Standard Deviation \( \sigma_X \)
Review
Topic 4.9
~5 min
Review
Combining Random Variables
Combining Random Variables
  • Linear Transformations of a Random Variable
  • Linear Combinations of Random Variables
  • Means of Sums and Differences
Review
Topic 4.10
~6 min
Review
Introduction to the Binomial Distribution
Introduction to the Binomial Distribution
  • What a Binomial Random Variable Is
  • The Binomial Probability Formula
  • Finding Binomial Probabilities
Review
Topic 4.11
~5 min
Review
Parameters for a Binomial Distribution
Parameters for a Binomial Distribution
  • What a Binomial Random Variable Is
  • The Parameters of a Binomial Distribution
  • What These Formulas Mean Conceptually
Review
Topic 4.12
~5 min
Review
The Geometric Distribution
The Geometric Distribution
  • What a Geometric Random Variable Is
  • The Geometric Probability Formula
  • Mean and Standard Deviation
Review

Notes

1 credit used · 5/5 remaining