find the equation that represents the proportional relationship in this graph, for y in terms of x.

Explanation:

Step1: Recall proportional - relationship formula

A proportional relationship has the form $y = kx$, where $k$ is the constant of proportionality.

Step2: Find the value of $k$

We can use a point on the line. Let's take the point $(15, 30)$. Substitute $x = 15$ and $y = 30$ into $y=kx$. Then $30=k\times15$. Solving for $k$, we get $k=\frac{30}{15}=2$.

Step3: Write the equation

Substitute $k = 2$ into $y = kx$. The equation is $y = 2x$.

Answer:

$y = 2x$