Ratios

A ratio is a measure of the relative size of two classes (groups) that is expressed as a proportion. For example, any group of humans can be divided into two classes, male and female. If in a group of 60 humans there are 40 males and 20 females, then the ratio of males to females is 40 to 20. This is usually expressed as a ratio which is simplified to 2 to 1 and is written 2:1. If our group of 60 humans comprised 35 males and 25 females the ratio of males to females would be 7:5. For easy comparisons, ratios are often obtained by dividing the value of the smallest group into the value of each larger group. In which case, all ratios have their smallest value as one. For example, our ratio of 7:5 would be 7 ÷ 5 = 1.4 which is written as 1.4:1.