This is the ubiquitous bell-shaped curve. Some phenomena such as heights seem to naturally follow this distribution, whilst others, including coin-toss scores (the Binomial distribution), end up looking approximately Normal for sufficiently many tosses. This theoretical distribution is also known as a Normal distribution.

Used on pages 4, 5, 43, 44, 47, 48, 49, 50, 51, 52, 53, 67, 77, 81, 84, 86, 87, 93

Also known as Gaussian distribution, Normally distributed