Probability
Where probability shows up in real life
8 live exhibits. Each one already works. Change a number and see what happens.
Open as board Play with these together. Solving one grows related exhibits.
ProbabilityDice odds: what are my chances of rolling it?
Why 7 shows up so often with two dice, and what that means for your next move.
StatisticsThe bell curve: what percentile is that?
Count standard deviations from the average (the z-score), and the bell curve tells you what share falls below.
ProbabilityThe birthday problem: 23 people is a coin flip
In a room of 23, it’s better than even that two share a birthday. Every pair is a chance, and pairs add up fast.
ProbabilityLottery odds: what is a ticket really worth?
Powerball is 1 in 292 million. Multiply the chance by the prize, after the lump sum, taxes, and splitting, and see what $2 buys.
ProbabilityMonty Hall: should you switch doors?
Pick a door, watch the host open an empty one, then decide. Switching wins two times out of three, and here you can watch it happen.
StatisticsA/B test: is version B really better, or just lucky?
A higher conversion rate might be chance. The z-test turns the gap and the sample size into a p-value.
ProbabilityA 99% accurate test, and a positive is probably wrong
When something is rare, the few real cases are outnumbered by false alarms. Bayes’ rule counts both.
MatricesHow search ranks pages: links as votes (PageRank)
A link is a vote, and votes from important pages count more. Repeat until it settles and you get PageRank.