Direct and Inverse Proportion

A direct-proportion graph has horizontal axis \(x\) and vertical axis \(y\). It passes through \((4,10)\).

1. Find its equation.

2. Find \(y\) when \(x=6\).

3. Sketch the graph for \(x\geq0\), labelling the origin and the two known points.

4. Could the line \(y=2.5x+3\) represent direct proportion between \(y\) and \(x\)? Explain.