Answer:
C) 5
Step-by-step explanation:
The problem tell us that y is directly proportional to x, so we can represent this mathematically by:
[tex]y=c*x[/tex]
Where:
[tex]c=Proportionality\hspace{3}constant[/tex]
If we evaluate the data provided by the problem, then:
[tex]20=c*4[/tex]
Solving for c, dividing both sides by 4:
[tex]\frac{20}{4} =c*\frac{4}{4} \\5=c*1\\5=c[/tex]
Hence, the proportionality constant or the constant of variation is 5
