Answer
The missing value is: $8$
The equation is $y = \frac{2}{5}x$
Work Step by Step
The values of y seem to vary directly with the values of x.
Ratio:
$\frac{4}{10}=\frac{2}{5}$
$\frac{3.2}{8}=\frac{2}{5}$
The ratio $\frac{y}{x}$ is the same for all data pairs. So this is inverse variation, and $k =\frac{2}{5}$.
The missing value is: $8$ since $\frac{8}{20}=\frac{2}{5}$
An equation is $y = \frac{2}{5}x$.
