Since constant of variation k is calculated by dividing y-coordinate and x-coordinate .
From the given table we can see that
[tex]f(x)=-1\text{ when x=2}[/tex]
So
[tex]\begin{gathered} k=\frac{-1}{2} \\ =-0.5 \end{gathered}[/tex]
So constant of variation k is -0.5
