Which statement about the graph is true?

On a coordinate plane, a line goes through points (0, 2), (2, 3), (4, 4), (6, 5).
The graph shows a proportional relationship because it is a line, and the difference between each point is the same.
The graph shows a proportional relationship because it is a line, and each x-value is a multiple of 2.
The graph does not show a proportional relationship because each point written as a ratio gives a different value.
The graph does not show a proportional relationship because a line that increases by 1 in the y-value cannot have a constant of proportionality.

1 answer

To determine whether the statements regarding the graph are true or not, we should first analyze the given points and what a proportional relationship means.

A proportional relationship is typically described as one in which the ratio of \(y\) to \(x\) is constant. Mathematically, this could be expressed as \(y = kx\) for some constant \(k\).

Let's examine the points provided:

  • (0, 2): Here, the ratio \(y/x\) is undefined since we cannot divide by zero when \(x = 0\).
  • (2, 3): The ratio is \(3/2 = 1.5\).
  • (4, 4): The ratio is \(4/4 = 1\).
  • (6, 5): The ratio is \(5/6\).

Each of these ratios is different, indicating that the relationship is not constant.

Now let's analyze the statements:

  1. The graph shows a proportional relationship because it is a line, and the difference between each point is the same.

    • This is false. While the graph is a line, it does not mean it represents a proportional relationship. The differences between points are not consistent in terms of \(y/x\) ratios.
  2. The graph shows a proportional relationship because it is a line, and each x-value is a multiple of 2.

    • This is also false for the same reason as above. The x-values being multiples of 2 does not guarantee a proportional relationship as defined by a constant ratio.
  3. The graph does not show a proportional relationship because each point written as a ratio gives a different value.

    • This statement is true, as we have established that the ratios \(y/x\) are not constant.
  4. The graph does not show a proportional relationship because a line that increases by 1 in the y-value cannot have a constant of proportionality.

    • This statement is a bit misleading. The increase in the y-value is not the reason for the absence of proportionality; rather, it's the fact that the ratios between y and x are not consistent.

Thus, the true statement is:

The graph does not show a proportional relationship because each point written as a ratio gives a different value.