Statistics — Describing & Inferring
The normal curve & the 68–95–99.7 rule
continues from lesson 1 — values defined earlier in the course stay live here
ELI5: heap up enough independent measurements — heights, test scores, manufacturing errors — and they pile into the famous bell curve. The rule of thumb: about 68% of values land within 1 standard deviation of the mean, 95% within 2, and 99.7% within 3.
the bell curve — most of the area huddles near the centre
Real-world hook: the 68–95–99.7 rule sets manufacturing tolerances, defines IQ bands, and is why a "6-sigma" defect (6 std away) is treated as essentially impossible.