Answer:
The constant of variation is k=5
Step-by-step explanation:
Proportions
A direct proportion is a relation between variables where their ratio is a constant value. This means that if y and x are proportional, then:
[tex]y=k\cdot x[/tex]
Where k is the constant of proportionality.
We know R varies directly with S. Their relationship is:
[tex]R=k\cdot S[/tex]
We also have when S=16, R=80. Thus:
[tex]80=k\cdot 16[/tex]
Solving for k:
[tex]k=80/16=5[/tex]
The constant of variation is k=5