Percentage, Ratio and Proportion

Abstract

Per cent (symbol %) means per hundred, and a percentage may be considered as a common fraction with 100 as denominator

$$3\%=\frac{3}{{100}},\quad \;72\%=\frac{{72}}{{100}}\,\,or\,\,\frac{{18}}{{25}},\quad \quad 2\tfrac{1}{2}\%=\frac{5}{{200}}\,\,or\,\,\frac{1}{{40}}$$

A percentage may also be expressed as a decimal fraction, so that

$$7\%=7\div 100=0.07,\quad \quad 2.5\%=0.025,\quad \quad 100\%=1.00$$

To change a percentage to a fraction, divide by one hundred.