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:
\(y=c*x\)
Where:
\(c=Proportionality\hspace{3}constant\)
If we evaluate the data provided by the problem, then:
\(20=c*4\)
Solving for c, dividing both sides by 4:
\(\frac{20}{4} =c*\frac{4}{4} \\5=c*1\\5=c\)
Hence, the proportionality constant or the constant of variation is 5
