The Teri Aki Diner Is a New Buffet-Style Restaurant Offering

The Teri Aki Diner is a new buffet-style restaurant offering stir-fry and Thai dishes.The buffet has a fixed price of $8.50 per person.The estimated food costs are $2.00 per person,regardless of volume.Fixed costs are related to the number of buffet lines that are maintained,with the estimated costs as follows:
$$\begin{array} { | l | r | r | } \hline & \text { Monthy wolume } & \text { Fired Costs } \\\hline 1 \text { line } & 0 - 4,000 & \$ 30,000 \\\hline 2 \text { lines } & 4,001 - 6,000 & \$ 37,000 \\\hline 3 \text { lines } & 6,001 - 7,500 & \$ 40,000 \\\hline\end{array}$$
Required:
Determine the break-even point(s).