Description
When you drop marbles into the Galton board, they will distribute according to a fixed pattern. The game shows that the distribution follows a certain pattern. The chance that a ball repeatedly falls to one side is small, so more balls will end up in the middle of the board. We call this distribution a ‘normal’ distribution.
In everyday life, much is also normally distributed: the number of sweets in an (unopened!) candy bag, for example. This is because these are filled by a machine. In the process, sometimes one more or one less sweet ends up in the bag. This is allowed, within certain standards. Of course, you don’t want to buy a bag containing far fewer sweets than it says. Such a bag would fall outside the standard and be rejected.
In the future, companies will use this standard a lot. If you want to know if a car is still safe, all parts must work according to ‘the norm’. By measuring the performance of these parts, you can predict if, for example, you will need new tires or a new battery soon.
Why do the marbles divide in a pattern?
- Turn the ring to make all the marbles go up.
- Turn the board straight again to make all the marbles fall.
- Wait until all the marbles are down.
- Look at the pattern. What do you see?
