Final answer:
The constant of proportionality in the equation y = -3.38x is -3.38, indicating a straight line with a slope of -3.38 that passes through the origin on a graph.
Step-by-step explanation:
The constant of proportionality in the equation y = -3.38x is -3.38.
In a directly proportional relationship, the general form of the equation is y = kx, where k is the constant of proportionality. In this case, the equation suggests that y varies directly as x, but since the constant is negative, y decreases as x increases, indicating an inverse relationship in terms of direction but not in mathematical definition.
The graphical representation of this proportional relationship would be a straight line that passes through the origin with a slope of -3.38.