Final answer:
The equation y = 7.5x represents a straight line on a graph passing through the origin, indicating a proportional relationship with a slope of 7.5, meaning y increases by 7.5 for every increase of 1 in x with a y-intercept of 0.
Step-by-step explanation:
The graph of the proportional relationship represented by the equation y = 7.5x is a straight line that passes through the origin (0,0) with a slope of 7.5. This means for every increase of 1 in the value of x, the value of y will increase by 7.5. Since it is a direct relationship, the line is continuous and extends in both the positive and negative directions along the x-axis and y-axis. This relationship also indicates that the y-intercept is 0, as the line crosses the y-axis at the origin. Whenever x is zero, y will also be zero.