To determine the unit cost from the graph, we need to find the slope of the line that passes through the points (0, 0) and (4, 3). The slope (which represents the cost per marker) is calculated using the formula:
\[ \text{slope} = \frac{\Delta y}{\Delta x} = \frac{y_2 - y_1}{x_2 - x_1} \]
Using the points:
- \((x_1, y_1) = (0, 0)\)
- \((x_2, y_2) = (4, 3)\)
We substitute in the values:
\[ \text{slope} = \frac{3 - 0}{4 - 0} = \frac{3}{4} \]
This means the cost per marker is \(\frac{3}{4}\) dollars.
So, the unit cost from the graph is:
\[ \text{$0.75 per marker} \]