Worked Examples

Crosstab Examples

Famous contingency tables, fully worked through. Each example shows the real data, the chi-square test, the effect size, and a plain interpretation — and you can open any table directly in the calculator to explore it yourself.

These pages are complete chi-square and crosstab walkthroughs built on public datasets — from the Titanic passenger records to Doll and Hill's landmark smoking study. Two examples use illustrative data and are clearly marked as such. Every statistic on these pages is computed with the same engine that powers the calculators, so the numbers always match what you would get with your own data.

Titanic Survival by Sex

Did 'women and children first' show up in the numbers? Survival outcomes for the 2,201 people aboard the RMS Titanic, cross-tabulated by sex.

2×2 table · N = 2,201

Titanic Survival by Passenger Class

Survival on the Titanic broken down by ticket class and crew status — a classic 4×2 contingency table from the 1912 Board of Trade inquiry.

4×2 table · N = 2,201

Berkeley Admissions by Sex (1973)

The famous UC Berkeley graduate admissions table behind Simpson's paradox: 4,526 applicants cross-tabulated by sex and admission decision.

2×2 table · N = 4,526

Smoking and Lung Cancer (Doll & Hill, 1950)

The landmark case-control study linking smoking to lung cancer: 649 male lung-cancer patients and 649 matched controls by smoking status.

2×2 table · N = 1,298

Aspirin and Heart Attack (Physicians' Health Study)

A randomized trial of 22,071 US male physicians: did low-dose aspirin reduce the rate of first myocardial infarction versus placebo?

2×2 table · N = 22,071

Snoring and Heart Disease

An epidemiological survey of 2,484 adults relating snoring frequency to heart disease — a standard ordinal-by-binary example from Agresti.

4×2 table · N = 2,484

Product Preference by Age Group

An illustrative market-research crosstab: 300 survey respondents in three age bands choosing between three products.

3×3 table · N = 300 · illustrative

Customer Churn by Billing Plan

An illustrative SaaS retention crosstab: churn over twelve months for 500 monthly-plan and 500 annual-plan customers.

2×2 table · N = 1,000 · illustrative