Answer:
[tex]k=5[/tex]
Step-by-step explanation:
[tex]y \propto x[/tex]
[tex]y=kx[/tex]
[tex]y=k \times x[/tex]
[tex]20= k \times 4[/tex]
[tex]20/4=k[/tex]
[tex]5=k[/tex]
The constant variation in a direct variation is the constant ratio [tex]k[/tex].
