Proportions

Definition

Proportions refer to the relationship between two or more quantities where the ratio between them remains constant. This concept is fundamental in solving equations with fractions or decimals, as well as in understanding mixture applications.

5 Must Know Facts For Your Next Test

1. Proportions are used to represent the relationship between two or more quantities as a fraction, where the ratio between them remains constant.
2. In solving equations with fractions or decimals, proportions are used to find unknown values by setting up an equation with equivalent ratios.
3. Mixture applications, such as calculating the concentration of a solution or the composition of a mixture, often involve the use of proportions to determine the unknown quantities.
4. Equivalent fractions can be used to represent proportions, where the ratios between the numerators and denominators are the same.
5. Cross-multiplication is a common method for solving proportions, where the product of the numerators is equal to the product of the denominators.

Review Questions

• Explain how proportions can be used to solve equations with fractions or decimals.
  • Proportions are used to solve equations with fractions or decimals by setting up an equation with equivalent ratios. For example, if you have the equation $\frac{x}{4} = \frac{3}{8}$, you can set up a proportion $\frac{x}{4} = \frac{3}{8}$ and use cross-multiplication to solve for the unknown value of $x$. This method allows you to find the missing value while maintaining the constant ratio between the quantities.
• Describe how proportions are applied in mixture applications.
  • Mixture applications, such as calculating the concentration of a solution or the composition of a mixture, often involve the use of proportions. For instance, if you have a mixture of two substances, you can use proportions to determine the relative amounts of each substance. By setting up an equation with the known and unknown quantities as a proportion, you can solve for the missing value and understand the composition of the mixture.
• Analyze the role of equivalent fractions in representing proportions.
  • Equivalent fractions are crucial in representing proportions because they maintain the same ratio between the numerators and denominators. When working with proportions, you can use equivalent fractions to set up an equation with the same constant ratio, which is essential for solving for unknown values. By understanding the relationship between equivalent fractions and proportions, you can more effectively manipulate and solve problems involving fractions and ratios.

Related terms

Ratio: The relationship between two quantities expressed as a fraction or percentage.

Equivalent Fractions: Fractions that represent the same value despite having different numerators and denominators.

Cross-Multiplication: A method of solving proportions by multiplying the numerators and denominators of the fractions to find an unknown value.