Statistics teaching aid for illustrating binomial distribution - uses balls passing through grid to fall into vertical channels

摘要

The statistics teaching acid which is used to illustrate a binomial distribution comprises a base plate (10) which has a storage hopper holder a number of balls at the top. A selected number of balls (20) can be released so as to fall through a grid (21) of projecting pins (22) in parallel rows and into adjacent vertical channels (24) beneath the bottom row of pins (22). The channels (24) are aligned with the spaces between the pins (22) of the bottom row each of these spaces being slightly wider than the diameter of the balls (20).