3.1(b) Proportion

(b) Proportion

A proportion is a statement, which is expressed as an equivalence of two ratios.

If two ratios $a:b$ and $c:d$ are equal, then we can write $a:b = c:d$

Where quantities $a,d$ are called extremes, while $b,c$ are called means.

Symbolically the proportion of $a,b,c$ and $d$ is written as

or $a:b = c:d$