The proportional equation in the graph is y = (9/7)*x.
How to find the proportional equation?
Remember that a general proportional equation between two variables x and y is written as:
y = k*x
Where k is the constant of proportionality.
Looking at the graph we can see that the line passes through the point (7, 9), replacing these values we will get:
9 = k*7
Solving for k:
9/7 = k
Then the equation is:
y = (9/7)*x