Answer
The missing value is: $0.9$
An equation is $y = 70x$.
Work Step by Step
The values of y seem to vary directly with the values of x.
Ratio:
$\frac{28}{0.4}=70$
$\frac{84}{1.2}=70$
The ratio $\frac{y}{x}$ is the same for all data pairs. So this is inverse variation, and $k =70$.
The missing value is: $0.9$ since $\frac{63}{0.9}=70$
An equation is $y = 70x$.
