Answer:
k=3.5, and y=3.5x is the equation of the line
Step-by-step explanation:
y and x are proportional means that y = kx for some constant k.
Thus, when y=7 and x=2, we have that 7 = k * 2, so that k = 7/2 = 3.5,
and the equation of the line is y = 3.5x
