#### Answer

$\frac{4.2}{8.4}=\frac{1}{2}$ is called a [proportion] while $\frac{7}{8}$ is a [ratio].

#### Work Step by Step

A proportion is an equality statement with a left-hand side, right-hand side, and an equals sign, and the left-hand side and the right-hand side are ratios.
A ratio is simply a fraction.