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Bean machine

The Bean Machine, also known as the Quincunx, is a device invented by Sir Francis Galton to demonstrate the law of error and the normal distribution.

The machine consists of a vertical board with interleaved rows of pins. Balls are dropped from the top, and bounce randomly left and right as they hit the pins. Eventually, they are collected into one-ball-wide bins at the bottom. The height of ball columns in the bins approximates a bell curve.

See also: pachinko

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