Proportion

A proportion ratios. $\frac{a}{b}$ and $\frac{c}{d}$ such that $\frac a b= \frac c d$The ratio $\frac{a}{b}$ or $\frac{c}{d}$ can be simplified and then make more complex to make the other.

Proportions can be used in Arithmetic or Algebra, it is when two ratios are set equal to each other. The ratios in proportions can be wrote as fractions $\frac a b= \frac c d$ or normal divisions $a:b=c:d$ and pronounced a to b equal c to d.

In proportions the two terms in the middle are called means when the other two on the sides are called extremes, for example the means in a:b=c:d are b and c and the extremes are a and d. Instead in the ratios the first term is called antecedent and the other is called consequent, for example in a/b, the antecedent is a and the consequent is b.