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Probability Diagrams

Every diagram used on the probability pages, in one place: 185 diagrams from 69 pages. Open one to read its explanation and jump to the exact section where it appears.

185 of 185

The 36 outcomes of two dice, each with probability 1/36

Probability Axioms: Foundation of Probability Theory › The Probability Axioms (Overview)

Branches below A carry P(B given A) and P(not B given A)

Bayes' Theorem › Connection to Conditional Probability

One outcome highlighted across every branch of the partition

Bayes' Theorem › The Role of Total Probability

Binomial CDF, n = 10, p = 0.5: a staircase

CDF (Cumulative Distribution Function) › Discrete Random Variables

Normal CDF, mean 0, standard deviation 1

CDF (Cumulative Distribution Function) › Continuous Random Variables

Continuous uniform CDF, a = 0, b = 10: a straight ramp

CDF (Cumulative Distribution Function) › Using the CDF to Compute Probabilities

The standard normal density, the limit shape of averages

Central Limit Theorem: Sample Means and Normal Distribution › Central Limit Theorem Notation

Sum equals 7: six of the 36 equally likely cells

Combinatorics in Probability: Counting and Classical Formula › Finite Sample Spaces and Counting

Three tosses: the eight sequences of heads and tails

Combinatorics in Probability: Counting and Classical Formula › Counting in Classical Probability Experiments

Given A: only the subtree below A remains

Conditional Probability: P(A|B) Formula and Examples › Formal Meaning of Conditional Probability

Event A across three compartments, the middle one selected

Conditional Probability: P(A|B) Formula and Examples › Visual Representations

A 2 by 2 contingency table with row and column totals

Conditional Probability: P(A|B) Formula and Examples › Examples

Even sum: 18 of the 36 outcomes of two dice

Events in Probability: Sample Space and Event Operations › Sample Space and Events

Two events A and B with their intersection selected

Events in Probability: Sample Space and Event Operations › Set-Theoretic View

Given A: the subtree below A

Events in Probability: Sample Space and Event Operations › Conditional Events

A distribution pulled to the right: the mean follows the weight

Expected Value Page › The Intuition Behind Expected Value

A discrete distribution with E[X] = 3.4

Expected Value Page › Expected Value for Discrete Random Variables (PMF)

A waffle chart with equal columns: independence

Independence of Events › Visual Representations

A 2 by 2 contingency table

Independence of Events › Common Mistakes

Majority heads: the four sequences where the indicator equals 1

Indicator Random Variables: Converting Events to 0-1 Variables › From Events to Random Variables

A 2 by 3 contingency table with marginal totals

Joint Probability: Combined Outcomes for Multiple Variables › Joint Probability Notation

One path through the tree: the joint probability of A and B

Joint Probability: Combined Outcomes for Multiple Variables › Connection to Conditional Probability

Standard normal density: the shape the central limit theorem adds

Law of Large Numbers: Sample Mean Convergence › LLN vs Central Limit Theorem

Exponential CDF, lambda = 1: the median is where F crosses one half

Median: 50th Percentile of Distributions › Median for Continuous Distributions

Normal CDF, mean 0, standard deviation 1

Median: 50th Percentile of Distributions › How to Find the Median

Poisson PMF, lambda = 3: two bars tie for the peak

Mode: Peak Probability Concentration › Mode for Discrete Distributions

Exponential density, lambda = 1: the peak sits at zero

Mode: Peak Probability Concentration › Mode for Continuous Distributions

Three tosses labelled by the number of heads

Random Variables: Mapping Outcomes to Numbers › From Outcomes to Numerical Values

Normal density: a continuous random variable

Random Variables: Mapping Outcomes to Numbers › Types of Random Variables

Binomial CDF, n = 10, p = 0.5: the statement X ≤ k

Random Variables: Mapping Outcomes to Numbers › Random Variables and Probability Statements

The sample space of two dice: 36 ordered outcomes

Sample Space: All Possible Outcomes in Probability › Definition of Sample Space

Even sum: an event as a subset of the sample space

Sample Space: All Possible Outcomes in Probability › Relationship to Events

Three coin tosses: eight equally likely sequences

Sample Space: All Possible Outcomes in Probability › Sample Space in Practice

Two events with their intersection selected

Sets in Probability: Foundation for Events and Models › Core Set Operations in Probability

Three events inside a sample space, the outside region selected

Sets in Probability: Foundation for Events and Models › How Sets Become Events

A three-way partition and its outcomes

Law of Total Probability: Weighted Case Analysis › Splitting a Probability Across Cases

Event A drawn across a three-compartment partition

Law of Total Probability: Weighted Case Analysis › Diagrammatic Representations

The first case highlighted: its contribution to the total

Law of Total Probability: Weighted Case Analysis › Why the Law Works

The subtree below A: branch weights are conditional probabilities

Tree Diagrams: Visualizing Sequential Probability › Tree Diagrams and Conditional Probability

One outcome highlighted across every branch

Tree Diagrams: Visualizing Sequential Probability › Tree Diagrams and the Law of Total Probability

One complete path: multiply along the branches

Tree Diagrams: Visualizing Sequential Probability › Using Tree Diagrams to Compute Probabilities

A dataset around its mean of 20

Variance: Measuring Spread in Probability › Variance Notation

The same dataset with the sample variance

Variance: Measuring Spread in Probability › Calculating Variance: General Case

A high-variance dataset

Variance: Measuring Spread in Probability › Variance vs Standard Deviation

Binomial PMF, n = 10, p = 0.5

Probability Distributions: Discrete & Continuous › Probability Function

Normal CDF, mean 0, standard deviation 1

Probability Distributions: Discrete & Continuous › Cumulative Distribution Function (CDF)

Continuous uniform density, a = 0, b = 10

Title › Continuous vs Discrete Distributions

Standard normal density

Title › Types of Continuous Distributions

Exponential CDF, lambda = 1

Title › Working with PDFs and CDFs

Exponential density, lambda = 1

Exponential Distribution: PDF, CDF & Properties › Probability Density Function (PDF) and Support (Range)

Exponential CDF, lambda = 1

Exponential Distribution: PDF, CDF & Properties › Cumulative Distribution Function (CDF)

Normal density, mean 0, standard deviation 1

Normal Distribution: Bell Curve, PDF & Z-Scores › Probability Density Function (PDF) and Support (Range)

Normal CDF, mean 0, standard deviation 1

Normal Distribution: Bell Curve, PDF & Z-Scores › Cumulative Distribution Function (CDF)

Continuous uniform density, a = 0, b = 10

Continuous Uniform Distribution: PDF, Mean & Variance › Probability Density Function (PDF) and Support (Range)

Continuous uniform CDF, a = 0, b = 10

Continuous Uniform Distribution: PDF, Mean & Variance › Cumulative Distribution Function (CDF)

Discrete uniform PMF, values 1 to 6

Title › What Makes a Distribution Discrete

Binomial CDF, n = 10, p = 0.5

Title › Discrete vs Continuous Distributions

Binomial PMF, n = 10, p = 0.5

Binomial Distribution: PMF, Mean & Variance › Probability Mass Function (PMF) and Support (Range)

Binomial CDF, n = 10, p = 0.5

Binomial Distribution: PMF, Mean & Variance › Cumulative Distribution Function (CDF)

Three tosses: eight sequences grouped by number of heads

Binomial Distribution: PMF, Mean & Variance › Applications and Examples

Geometric PMF, p = 0.3

Geometric Distribution: PMF, Mean & Memoryless › Probability Mass Function (PMF) and Support (Range)

Geometric CDF, p = 0.3

Geometric Distribution: PMF, Mean & Memoryless › Cumulative Distribution Function (CDF)

Hypergeometric PMF, N = 50, K = 20, n = 10

Hypergeometric Distribution: Sampling Without Replacement › Probability Mass Function (PMF) and Support (Range)

Hypergeometric CDF, N = 50, K = 20, n = 10

Hypergeometric Distribution: Sampling Without Replacement › Cumulative Distribution Function (CDF)

Negative binomial PMF, r = 3, p = 0.4

Negative Binomial Distribution: Trials Until r Successes › Probability Mass Function (PMF) and Support (Range)

Negative binomial PMF with the mean marked

Negative Binomial Distribution: Trials Until r Successes › Expected Value (Mean)

Poisson PMF, lambda = 3

Poisson Distribution: Event Counts & Rate Parameter › Probability Mass Function (PMF) and Support (Range)

Poisson CDF, lambda = 3

Poisson Distribution: Event Counts & Rate Parameter › Cumulative Distribution Function (CDF)

Discrete uniform PMF, a = 1 to b = 6

Discrete Uniform Distribution: Equal Probability Outcomes › Probability Mass Function (PMF) and Support (Range)

Discrete uniform CDF, a = 1 to b = 6

Discrete Uniform Distribution: Equal Probability Outcomes › Cumulative Distribution Function (CDF)

A dataset with its mean and squared deviations

Probability Inequalities: Bounds Without Full Distributions › What Inequalities Depend On

Chebyshev bound for a normal variable, mean 10, variance 4, deviation 3

Probability Inequalities: Bounds Without Full Distributions › Featured Inequalities

Chebyshev bound for a normal variable, mean 10, variance 4, deviation 3

Chebyshev's Inequality › Statement of Chebyshev's Inequality

Chebyshev bound for a uniform variable

Chebyshev's Inequality › Limitations of Chebyshev's Inequality

Markov bound for an exponential variable, mean 10, threshold 15

Markov Inequality › Statement of Markov's Inequality

A threshold below the mean: the bound exceeds 1 and says nothing

Markov Inequality › Limitations of Markov's Inequality

A probability model: three tosses, eight outcomes, each 1/8

Probability Models: Mathematical Frameworks for Randomness › What Is a Probability Model

Discrete uniform PMF, values 1 to 6

Probability Models: Mathematical Frameworks for Randomness › Models, Random Variables, and Distributions

Two dice: a finite model with 36 outcomes

Probability Models: Mathematical Frameworks for Randomness › Simple Discrete Models

Three tosses: the eight outcomes

Coin Toss Probability Model: Binary Outcomes and Distributions › Outcome Space

Majority heads: four of the eight sequences

Coin Toss Probability Model: Binary Outcomes and Distributions › Events

Binomial PMF, n = 10, p = 0.5: heads in ten tosses

Coin Toss Probability Model: Binary Outcomes and Distributions › Distributions Built from Repeated Coin Tosses

Two dice: 36 ordered outcomes

Dice Roll Probability Model: Finite Multi-Outcome Randomness › Outcome Space

Sum equals 7: six outcomes on the diagonal

Dice Roll Probability Model: Finite Multi-Outcome Randomness › Events

Discrete uniform PMF, a = 1 to b = 6

Dice Roll Probability Model: Finite Multi-Outcome Randomness › Distributions Directly Induced by a Single Roll

Binomial PMF, n = 10, p = 0.5

Probability Function: PMF and PDF Explained › Probability Mass Function (PMF)

Normal density, mean 0, standard deviation 1

Probability Function: PMF and PDF Explained › Probability Density Function (PDF)

Normal density, mean 0, standard deviation 1

Probability Density Function (PDF) › Definition & Physical Intuition

Normal CDF, mean 0, standard deviation 1

Probability Density Function (PDF) › Connection to CDF (The Fundamental Theorem)

Exponential density, lambda = 1, with the mean marked

Probability Density Function (PDF) › PDFs of Common Continuous Distributions

Binomial PMF, n = 10, p = 0.5

Probability Mass Function (PMF) › Definition & Physical Intuition

Binomial CDF, n = 10, p = 0.5

Probability Mass Function (PMF) › Connection to CDF

Discrete uniform PMF with its mean marked

Probability Mass Function (PMF) › PMFs of Common Discrete Distributions

Discrete uniform, a = 1 to b = 6

Discrete Distributions CDF Visualizer › Discrete Uniform: Equal Steps

Binomial, n = 10, p = 0.5

Discrete Distributions CDF Visualizer › Binomial: a Symmetric S-Curve

Geometric, p = 0.3

Discrete Distributions CDF Visualizer › Geometric: Never Quite Reaching 1

Negative binomial, r = 3, p = 0.4

Discrete Distributions CDF Visualizer › Negative Binomial: Waiting for Several Successes

Hypergeometric, N = 50, K = 20, n = 10

Discrete Distributions CDF Visualizer › Hypergeometric: Sampling Without Replacement

Poisson, lambda = 3

Discrete Distributions CDF Visualizer › Poisson: Counting Rare Events

Continuous uniform, a = 0 to b = 10

Continuous Distributions CDF Visualizer › Continuous Uniform: a Straight Line

Normal, mean 0, standard deviation 1

Continuous Distributions CDF Visualizer › Normal: the S-Curve and the 68-95-99.7 Rule

Exponential, lambda = 1

Continuous Distributions CDF Visualizer › Exponential: Fast Rise, Asymptotic Tail

Discrete uniform, a = 1 to b = 6

Discrete Probability Distributions › Discrete Uniform: Six Equal Bars

Binomial, n = 10, p = 0.5

Discrete Probability Distributions › Binomial: a Symmetric Peak at the Mean

Geometric, p = 0.3

Discrete Probability Distributions › Geometric: Decay from the First Bar

Negative binomial, r = 3, p = 0.4

Discrete Probability Distributions › Negative Binomial: the Peak Moves Off the First Bar

Hypergeometric, N = 50, K = 20, n = 10

Discrete Probability Distributions › Hypergeometric: Sampling Without Replacement

Poisson, lambda = 3

Discrete Probability Distributions › Poisson: Two Modes at an Integer Rate

Continuous uniform on [0, 10]: PDF above, CDF below

Continuous Probability Distributions › Continuous Uniform: a Flat Density and a Straight CDF

Normal, mean 0, sigma 1: PDF above, CDF below

Continuous Probability Distributions › Normal: the Bell and the Sigmoid

Exponential, lambda = 1: PDF above, CDF below

Continuous Probability Distributions › Exponential: Peak at Zero, Tail Without End

Full sample space, nothing highlighted

Dice Roll Probability Simulator and Calculator › The Full Sample Space for Two Dice

Sum equals 7 highlighted

Dice Roll Probability Simulator and Calculator › Highlighting a Sum: Why 7 Is the Peak

Doubles highlighted

Dice Roll Probability Simulator and Calculator › Doubles: a Structural Event

Even sums highlighted

Dice Roll Probability Simulator and Calculator › An Even Sum: Half the Grid

Full sample space, nothing highlighted

Coin Toss Probability Simulator and Calculator › The Full Sample Space for Three Coins

Heads majority highlighted

Coin Toss Probability Simulator and Calculator › A Majority of Heads

All three matching highlighted

Coin Toss Probability Simulator and Calculator › All Three the Same

Alternating outcomes highlighted

Coin Toss Probability Simulator and Calculator › Alternating Outcomes

Default tree, nothing highlighted

Total Probability Visualizer › The Default Tree

Branch A1 highlighted

Total Probability Visualizer › Following a Single Branch

Outcome B2 highlighted across every branch

Total Probability Visualizer › Summing Across Branches: the Law Itself

A four-part partition

Total Probability Visualizer › Changing the Partition Size

2×2 table, frozen

Interactive Contingency Tables Visualizer › The 2×2 Table: Two Events and Their Complements

2×3 table, frozen

Interactive Contingency Tables Visualizer › The 2×3 Table: One Event Against Three Outcomes

2×4 table, frozen

Interactive Contingency Tables Visualizer › The 2×4 Table: Four Outcomes

3×3 table, frozen

Interactive Contingency Tables Visualizer › The 3×3 Table: Both Variables Partitioned

The tree at P(A) = 0.6, P(B|A) = 0.7, P(B|not A) = 0.3

Tree Diagram - Conditional Probability Visualization › The Tree at Its Opening Settings

The A then B path highlighted

Tree Diagram - Conditional Probability Visualization › One Path: the Multiplication Rule

Both paths that reach B highlighted

Tree Diagram - Conditional Probability Visualization › Two Paths: the Law of Total Probability

The whole subtree under A highlighted

Tree Diagram - Conditional Probability Visualization › A Whole Subtree: Where the Ones Live

Three equal compartments with event A across them

Venn Diagram - Conditional Probability Visualization › The Three-Compartment Partition

Compartment B2 selected

Venn Diagram - Conditional Probability Visualization › Selecting a Compartment: Conditioning as Restriction

The same event A over four compartments

Venn Diagram - Conditional Probability Visualization › Four Compartments: More Pieces, Same Total

Four 10x10 grids at 0.15, 0.40, 0.65 and 0.85

Waffle Chart - Conditional Probability Visualization › The Four Grids at Their Opening Rates

Every region set to 0.5

Waffle Chart - Conditional Probability Visualization › Setting Every Region Equal

The 2x2 table at P(A) = 0.6, P(B|A) = 0.7, P(B|not A) = 0.3

Contingency Table - Conditional Probability Visualization › The Table at Its Opening Settings

Binomial, n = 10, p = 0.5: PMF above, CDF below

Binomial Distribution Calculator › The Explorer at Its Opening Parameters

Geometric, p = 0.3: PMF above, CDF below

Geometric Distribution Calculator › The Explorer at Its Opening Parameter

Negative binomial, r = 5, p = 0.3: PMF above, CDF below

Negative Binomial Distribution Calculator › The Explorer at Its Opening Parameters

Poisson, lambda = 3: PMF above, CDF below

Poisson Distribution Calculator › The Explorer at Its Opening Parameter

Hypergeometric, N = 50, K = 20, n = 10: PMF above, CDF below

Hypergeometric Distribution Calculator › The Explorer at Its Opening Parameters

Discrete uniform, a = 1 to b = 6: PMF above, CDF below

Discrete Uniform Distribution Calculator › The Explorer at Its Opening Range

Normal, mu = 0, sigma = 1: PDF above, CDF below

Normal Distribution Calculator › The Explorer at Its Opening Parameters

Exponential, lambda = 1: PDF above, CDF below

Exponential Distribution Calculator › The Explorer at Its Opening Parameter

Continuous uniform, a = 0, b = 10: PDF above, CDF below

Continuous Uniform Distribution Calculator › The Explorer at Its Opening Bounds

Default dataset, frozen

Interactive Variance Calculator and Visualizer › The Default Dataset

Low Variance preset, frozen

Interactive Variance Calculator and Visualizer › Low Variance: Points Clustered on the Mean

High Variance preset, frozen

Interactive Variance Calculator and Visualizer › High Variance: Points Pushed to the Extremes

Outliers preset, frozen

Interactive Variance Calculator and Visualizer › A Single Outlier

Default dataset with the sample toggle, frozen

Interactive Variance Calculator and Visualizer › The Sample Toggle: Dividing by n − 1

Equal Weights preset

Weighted Expected Value Visualizer › Equal Weights: E(X) Is the Simple Average

Pull Right preset

Weighted Expected Value Visualizer › Pull Right: Weight Toward the High Values

Pull Left preset

Weighted Expected Value Visualizer › Pull Left: the Mirror Image

Pull Center preset

Weighted Expected Value Visualizer › Pull Center: Same E(X), Different Distribution

Pull Extremes preset

Weighted Expected Value Visualizer › Pull Extremes: Same E(X) Again, from the Opposite Shape

Strong Right Bias preset

Weighted Expected Value Visualizer › Strong Right Bias: the Largest Pull

Strong Left Bias preset

Weighted Expected Value Visualizer › Strong Left Bias: the Mirror of the Largest Pull

The opening distribution

Discrete Expected Value Visualization › The Opening Distribution

After dragging P(X = 1) to its maximum

Discrete Expected Value Visualization › Why the Sliders Renormalise

Normal, E[X] = 10, a = 15

Markov Inequality Visualizer › Normal: the Bound Against a Bell Curve

Exponential, E[X] = 10, a = 15

Markov Inequality Visualizer › Exponential: Where Markov Is Tightest Among the Continuous Options

Uniform on [0, 20], a = 15

Markov Inequality Visualizer › Uniform: the Largest Tail of the Nine

Poisson, lambda = 10, a = 15

Markov Inequality Visualizer › Poisson: a Discrete Tail Read as Stems

Binomial, n = 25, p = 0.4, a = 15

Markov Inequality Visualizer › Binomial: the Bound at Its Loosest but One

Geometric, p = 0.1, a = 15

Markov Inequality Visualizer › Geometric: Heavy Tail, Truncated Window

Negative binomial, r = 5, p = 1/3, a = 15

Markov Inequality Visualizer › Negative Binomial: Five Successes at a Time

Hypergeometric, N = 50, K = 30, n = 17, a = 15

Markov Inequality Visualizer › Hypergeometric: Where the Bound Is Almost Meaningless

Discrete uniform on 1..19, a = 15

Markov Inequality Visualizer › Discrete Uniform: the Discrete Twin of the Flat Case

Exponential with a = 8, below E[X] = 10

Markov Inequality Visualizer › When Markov Becomes Useless

Normal, mu = 10, sigma^2 = 4, a = 3

Chebyshev Inequality Visualizer › Normal: the Bound at Its Most Familiar

Exponential, lambda = 0.1

Chebyshev Inequality Visualizer › Exponential: When the Bound Says Nothing

Continuous uniform on [6.54, 13.46]

Chebyshev Inequality Visualizer › Continuous Uniform: the Other Slider-Driven Case

Poisson, lambda = 10

Chebyshev Inequality Visualizer › Poisson: Variance Fixed by the Mean

Binomial, n = 25, p = 0.4

Chebyshev Inequality Visualizer › Binomial: the Bound Starts to Bite

Geometric, p = 0.1

Chebyshev Inequality Visualizer › Geometric: the Widest Spread on the Page

Negative binomial, r = 5, p = 1/3

Chebyshev Inequality Visualizer › Negative Binomial: Between the Two Extremes

Hypergeometric, N = 50, K = 30, n = 17

Chebyshev Inequality Visualizer › Hypergeometric: the Tightest Bound Here

Discrete uniform on 1..19

Chebyshev Inequality Visualizer › Discrete Uniform: Spread Without a Tail

Student Survey: P(A) = 0.6, P(B) = 0.4, P(A and B) = 0.15

2-Set Venn Diagram Tool › Student Survey: Four Regions That Reproduce the Marginals

Health Screening: P(A) = 0.2, P(B) = 0.3, P(A and not B) = 0.05

2-Set Venn Diagram Tool › Health Screening: Why the Two Conditionals Differ

Region 1 selected

2-Set Venn Diagram Tool › Selecting a Region

Demographics Study: P(A) = 0.5, P(B) = 0.5, P(C) = 0.62

3-Set Venn Diagram Tool › Demographics Study: Eight Regions That Reproduce Every Given

Region 1 selected: the triple intersection

3-Set Venn Diagram Tool › Why Four Constraints Are Needed, Not Two

Region 8 selected: outside all three circles

3-Set Venn Diagram Tool › Selecting a Region

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