Classical models built from the math you already know
Ten thermometers hang in the same room, each reading the true temperature plus its own small jitter: a manufacturing quirk, a draft, a fraction of a degree of noise nobody can remove. Read just one of them and that jitter is stuck to your answer. Average all ten, and something nice happens. The individual quirks tend to cancel, because one thermometer running high is just as likely as another running low. The averaged reading settles much closer to the true temperature than any single thermometer manages alone.
🔒 This is a Pro lesson — the interactive figure, worked examples, quiz and practice open with Pro access.
▶ Why Averaging Works: the Variance Math