The profit, P(x), that Rivka's Delivery Service makes from delivering packages between local businesses is P(x), where x is the number of $0.10 price increases for each delivery. Use the graph below to answer the question. Graph with x-axis labeled as number of price increases, and the y-axis labeled as profit. The curve begins at (0, 50), increases to (2.5, 81.25), and then decreases through (6.531, 0). What is the approximate number of price increases needed to cause zero profit?