1. **Problem Statement:** The graph of a business' profit function is given. We need to find the number of sales that should be targeted to earn the highest profit. 2. **Understanding the Problem:** The highest profit corresponds to the maximum point (vertex) of the profit function graph. 3. **Key Concept:** For a quadratic profit function of the form $$P(x) = ax^2 + bx + c$$ where $a < 0$, the maximum profit occurs at the vertex given by: $$x = -\frac{b}{2a}$$ 4. **From the graph:** The vertex (maximum point) is approximately at $x = 500$ sales. 5. **Conclusion:** The business should target **500 sales** to earn the highest profit. **Final Answer:** **500** sales