Robert recorded the number of miles he had biked every hour of a 4-hour bike trip. He graphed the results on the grid below.
The graph titled Robert's bike trip shows distance in miles on the vertical axis from 0 to 80 and time in hours from 0 to 4 on the horizontal axis. The points (0, 0), (1, 18), (2, 35), (3, 51) are joined to form a line.
Which statement BEST explains whether or not Robert’s graph represents a proportional relationship?
The statement "Robert’s graph represents a proportional relationship" is incorrect.
To determine whether or not the graph represents a proportional relationship, we would need to check if the ratio of distance to time remains constant for all points.
Let's calculate the ratios for the given points:
- For the points (0, 0) to (1, 18): The ratio is 18/1 = 18.
- For the points (1, 18) to (2, 35): The ratio is 35/1 = 35.
- For the points (2, 35) to (3, 51): The ratio is 51/1 = 51.
Since the ratios are different for each interval, the graph does not represent a proportional relationship.