Long description

Point of balance at the weighted mean. The figure shows a horizontal arrow pointing to the right and labelled pence. Three appropriately spaced points are marked on the line: 74.0, 76.9 and 81.6. The distance between the 74.0 and 76.9 is less than the distance between 76.9 and 81.6. Immediately below 76.9 there is a solid arrow head pointing upwards, which is the fulcrum or balancing point of the balance. Suspended from the point marked 74.0 is a pile of 8 discs and suspended from the point marked 81.6 is a pile of 5 discs.