Summary: Solving Proportions and their Applications

Key Concepts

• Proportion
  • A proportion is an equation of the form $\frac{a}{b}=\frac{c}{d}$ , where $b\ne 0$ , $d\ne 0$ .The proportion states two ratios or rates are equal. The proportion is read " $a$ is to $b$ , as $c$ is to $d$ ".
• Cross Products of a Proportion
  • For any proportion of the form $\frac{a}{b}=\frac{c}{d}$ , where $b\ne 0$ , its cross products are equal: $a\cdot d=b\cdot c$ .
• Percent Proportion
  • The amount is to the base as the percent is to 100. $\frac{\text{amount}}{\text{base}}=\frac{\text{percent}}{100}$

Glossary

proportion

A proportion is an equation of the form $\frac{a}{b}=\frac{c}{d}$ , where $b\ne 0$ , $d\ne 0$ .The proportion states two ratios or rates are equal. The proportion is read " $a$ is to $b$ , as $c$ is to $d$ ".

Licenses & Attributions