To find the unit cost from the graph, we can use the coordinates given. The line passes through the points (0, 0) and (4, 3).
The coordinates represent the following:
- (0, 0) means that when 0 markers are purchased, the total cost is $0.
- (4, 3) means that when 4 markers are purchased, the total cost is $3.
To find the unit cost per marker, we can calculate it using the formula:
\[ \text{Unit cost} = \frac{\text{Total cost}}{\text{Number of markers}} \]
Substituting the values from the point (4, 3):
\[ \text{Unit cost} = \frac{3}{4} = 0.75 \]
The unit cost per marker is $0.75.
So, the answer is:
$0.75 per marker.