USMLE purpose: Rapid-review a single biostats shortcut in Anki-card style.

How to use this page

1. Sketch the bell curve.
2. Mark the mean and SD.
3. Use 68–95–99.7.

• Episode metadata

One-liner

The area below +1 SD is 84%: 50% below the mean plus 34% from mean to +1 SD.

• Rapid recall: within 1 SD?
• Rapid recall: below +1 SD?

Extra practice

A normally distributed variable has mean 100 and SD 15. What percent is below 115?

• Reveal answer & explanation