Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

Start with one fact. Explore it, go deeper, then follow whichever branch catches your imagination.

Choose subjects for a surprise

Exploring any topic

Begin your discovery

Your next discovery is one click away.

Choose one or more subjects above, or leave Any Topic selected and let curiosity decide.

Mathematics

68-95-99.7 Rule

Quick fact

In a normal distribution, roughly 1 in 370 observations fall beyond three standard deviations from the mean, making such extreme values rare indeed.

Why this is interesting

Ever wonder how test scores, heights, or IQ scores are distributed? Why is it that most people score near the average, but a few are far above or below?