To solve this question, we need to find the value of k. We can obtain this value as follows:
[tex]3y=4x\Rightarrow y=\frac{4}{3}x\Rightarrow\frac{y}{x}=\frac{4}{3}[/tex]Then, the direct variation, k, is equal to 4/3, so that:
[tex]y=\frac{4}{3}x[/tex]k = 4/3