AP Statistics

AP Statistics Study Labs

Interactive study labs for the revised (2026–27) AP Statistics course, one for each of its 55 topics. Each lab has data you can edit, graphs and simulations that react, a running explanation of what changed and why, worked examples, FRQ tips, practice questions, and the key terms for that topic.

Terminology guides

Every key term in the course, with search, flashcards, and a self-quiz.

Unit 1 Exploring One-Variable Data and Collecting Data

20–30% of the multiple-choice section · Unit 1 terms
Topic 1.1

Introducing Statistics

Tell statistical questions from ordinary ones, then sample from a population to see why statistics vary while parameters stay fixed.

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Topic 1.2

Variables

Classify variables as categorical or quantitative (discrete or continuous) and see which summaries and graphs fit each type.

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Topic 1.3

Tables and Summaries for One Categorical Variable

Build frequency and relative frequency tables for a categorical variable and work backward from percents to counts.

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Topic 1.4

Graphs for One Categorical Variable

Display a categorical variable with bar charts and pie charts, and catch a misleading graph with a truncated axis.

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Topic 1.5

Graphs for One Quantitative Variable

Graph one quantitative variable as a dotplot, stemplot, histogram, or cumulative relative frequency plot, and see how bin choices change the picture.

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Topic 1.6

Describing Quantitative Distributions

Describe a quantitative distribution's shape, center, variability, and unusual features, and practice naming shapes from a histogram.

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Topic 1.7

Summary Statistics for One Quantitative Variable

Calculate the mean, median, standard deviation, quartiles, and IQR step by step, and see which ones resist outliers.

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Topic 1.8

Boxplots and Graphs of Summary Statistics

Build a boxplot from the five-number summary, flag outliers with the fences, and read percentiles off a cumulative relative frequency graph.

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Topic 1.9

Comparing Distributions

Compare two groups on shape, outliers, center, and spread with side-by-side dotplots and boxplots, and practice writing comparisons in context.

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Topic 1.10

The Investigative Question and Data Collection

Tell statistical questions from non-statistical ones, classify studies as census, sample survey, observational study, or experiment, and see how a confounding variable fakes a cause.

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Topic 1.11

Random Sampling

Sample a simulated school with simple random, stratified, cluster, and systematic sampling, and see which method gives the most precise estimates.

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Topic 1.12

Potential Problems with Sampling

Run a town survey six different ways and watch how undercoverage, nonresponse, voluntary response, convenience sampling, and question wording push the estimate away from the truth.

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Topic 1.13

Experimental Design

Run simulated experiments with self-selection, random assignment, blocking, and matched pairs to see how design controls bias and variability, then decide the scope of inference.

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Unit 2 Probability, Random Variables, and Probability Distributions

15–25% of the multiple-choice section · Unit 2 terms
Topic 2.1

Two-Way Tables and Graphs

Build a two-way table, then compare groups with side-by-side, segmented, and mosaic bar charts to see whether two categorical variables are associated.

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Topic 2.2

Summary Statistics for Two Categorical Variables

Click any cell of a two-way table to see its joint, marginal, and conditional relative frequencies, then practice picking the right denominator.

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Topic 2.3

Estimating Probabilities Using Simulation

Design and run a simulation with random numbers, then watch the estimated probability settle toward the true value as the number of trials grows.

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Topic 2.4

Introduction to Probability

List a sample space, count the outcomes in an event, and use the complement rule; then check whether a probability model is valid.

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Topic 2.5

Mutually Exclusive Events

Pick two events from a deck of cards, see their overlap in a Venn diagram, and decide whether they are mutually exclusive.

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Topic 2.6

Conditional Probability

Use a tree diagram and a table of hypothetical counts to find P(A and B), P(B), and P(A | B), and see why P(A | B) and P(B | A) can be very different.

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Topic 2.7

Independent Events and Unions of Events

Set P(A), P(B), and P(A and B), then check independence and find P(A or B) with the general addition rule.

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Topic 2.8

Random Variables and Probability Distributions

Build a discrete probability distribution, check that it is valid, and find probabilities like P(X ≤ 2) from the table and graph.

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Topic 2.9

Parameters of Random Variables

Find the mean (expected value) and standard deviation of a discrete random variable, then see how they change when you transform or combine variables.

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Topic 2.10

The Binomial Distribution

Check the binomial conditions, then set n and p to find exact, at-most, and at-least probabilities with binompdf and binomcdf.

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Topic 2.11

The Normal Distribution

Shade areas under a normal curve, convert to z-scores, and go both ways with normalcdf and invNorm.

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Topic 2.12

Sampling Distributions and the Central Limit Theorem

Draw thousands of random samples from skewed, uniform, or yes/no populations and watch the sampling distribution of the mean become approximately normal.

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Unit 3 Inference for Categorical Data: Proportions

15–25% of the multiple-choice section · Unit 3 terms
Topic 3.1

Estimators

Take hundreds of samples and see what makes an estimator biased or variable, and why bigger samples fix one but not the other.

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Topic 3.2

Sampling Distributions for Sample Proportions

Simulate thousands of samples to see the shape, center, and spread of p̂, and when the normal model and its conditions work.

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Topic 3.3

Confidence Interval for a Proportion

Build a one-proportion z-interval step by step, simulate hundreds of intervals to see what confidence means, and plan a sample size.

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Topic 3.4

Justifying a Claim with a Proportion Interval

Use a confidence interval as a set of plausible values to decide whether a claim about a population proportion is supported.

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Topic 3.5

Setting Up a Test for a Proportion

Practice writing null and alternative hypotheses, defining the parameter, and checking conditions for a one-proportion z-test.

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Topic 3.6

p-Values

See a p-value as a shaded area under the null model, compare it with a simulation, and practice interpreting it in context.

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Topic 3.7

Carrying Out a Test for a Proportion

Run a complete one-sample z-test for a proportion and get a four-step write-up (State, Plan, Do, Conclude) built from your inputs.

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Topic 3.8

Potential Errors When Performing Tests

See Type I error, Type II error, and power as areas under two sampling distributions, and how n, α, and the true p change them.

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Topic 3.9

Sampling Distributions for a Difference in Proportions

Simulate thousands of pairs of samples to see the center, spread, and shape of the sampling distribution of p̂₁ − p̂₂.

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Topic 3.10

Confidence Interval for a Difference in Proportions

Build a two-sample z-interval for p₁ − p₂ step by step, then simulate many intervals to see what the confidence level means.

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Topic 3.11

Justifying a Claim with a Two-Proportion Interval

Decide whether a confidence interval for p₁ − p₂ supports, fails to support, or contradicts a claim, and see what controls its width.

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Topic 3.12

Setting Up a Test for a Difference in Proportions

Write hypotheses for p₁ − p₂, pick the right alternative, and check conditions using the pooled proportion.

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Topic 3.13

Carrying Out a Test for a Difference in Proportions

Run a complete two-sample z-test for p₁ − p₂: pooled SE, test statistic, p-value, decision, and conclusion in context.

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Topic 3.14

Setting Up a Chi-Square Test

Decide between a chi-square test for homogeneity and for independence, write hypotheses, compute expected counts, and check conditions.

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Topic 3.15

Carrying Out a Chi-Square Test

Compute expected counts, components, the χ² statistic, df, and p-value for a two-way table, then write the conclusion in context.

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Unit 4 Inference for Quantitative Data: Means

10–20% of the multiple-choice section · Unit 4 terms
Topic 4.1

Sampling Distributions for Sample Means

Draw thousands of random samples from different population shapes and watch the distribution of sample means center at μ, shrink by σ/√n, and turn normal as n grows.

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Topic 4.2

Confidence Interval for a Mean or Mean Difference

Build a one-sample or paired t interval from raw data or summary statistics, check the conditions, and see what the confidence level really means.

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Topic 4.3

Justifying a Claim with a Mean Interval

Use a t interval for a mean or mean difference to decide whether a claimed value is plausible, and see how sample size and confidence level change the answer.

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Topic 4.4

Setting Up a Test for a Mean or Mean Difference

Practice choosing the parameter, hypotheses, procedure, and conditions for a one-sample or paired t test, and see which t values would count as evidence for the alternative.

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Topic 4.5

Carrying Out a Test for a Mean or Mean Difference

Run a one-sample or paired t test from raw data or summary statistics: compute t and the p-value, see the area on the t curve, and write all four steps.

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Topic 4.6

Sampling Distributions for a Difference in Means

Simulate thousands of differences in sample means and see why the mean is μ₁ − μ₂, the variances add, and the shape becomes normal.

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Topic 4.7

Confidence Interval for a Difference in Means

Build a two-sample t interval step by step, compare calculator and conservative df, and watch 50 intervals show what confidence means.

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Topic 4.8

Justifying a Claim with a Two-Mean Interval

Decide whether a claim about μ₁ − μ₂ is supported, plausible, or contradicted by a confidence interval, and see what makes the interval narrower.

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Topic 4.9

Setting Up a Test for a Difference in Means

Tell paired data from two independent samples, write hypotheses about μ₁ − μ₂, and check the Random, 10%, and Normal/Large conditions.

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Topic 4.10

Carrying Out a Test for a Difference in Means

Run a complete two-sample t-test: test statistic, df, a shaded p-value, the decision, and a four-step written answer that updates live.

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Unit 5 Regression Analysis

10–20% of the multiple-choice section · Unit 5 terms