A proportional relationship is characterized by a straight line that passes through the origin (0,0) and has a constant rate of change. Among the graphs described:
- Graph A shows a straight line with a negative slope, which does not indicate a proportional relationship since it does not pass through the origin in a positive manner.
- Graph B shows a straight line with a positive slope but has a y-intercept above the origin, which means it is not proportional.
- Graph C shows an increasing concave up curve initiating at the origin, which typically indicates a nonlinear relationship, not a proportional one.
- Graph D shows a straight line with a unit slope, indicating a consistent linear relationship that also passes through the origin.
Therefore, the graph that shows a proportional relationship is:
D