Ratio

A ratio is an expression of the magnitude of one quantity in relation to another. Ratios are typically expressed by two numbers separated by a colon, for instance, 4:3, read as ‘four to three’ and meaning that there are four units of the first items for every three units of the second item. Ratios do not require that the two numbers have common units and in fact are typically used to express the relationship between two quantities consisting of different units. For instance, the ratio of male to female patients in a hospital might be expressed as 2:1, meaning there were twice as many male patients as female patients or that there were two male patients for every one female patient.

The concept of ratio has ...