To find the marginal profit, which is the rate of change of profit with respect to the number of units sold, we need to determine the slope of the line represented by the two points given: (800, 3533) and (875, 8483).
The formula for the slope (m) of a line through two points \((x_1, y_1)\) and \((x_2, y_2)\) is given by:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
In this case, let:
- \((x_1, y_1) = (800, 3533)\)
- \((x_2, y_2) = (875, 8483)\)
Now, we can substitute these values into the formula:
\[ m = \frac{8483 - 3533}{875 - 800} \]
Calculating the changes in profit and units sold:
\[ m = \frac{4950}{75} \]
Now, performing the division:
\[ m = 66 \]
Thus, the marginal profit, or the rate of change of profit with respect to the number of units sold, is $66 per unit.