I don't see how a business owner would be interested in using inverse variation to drive his sales up. He must know something I don't. If he used the equation (sales) * cost = (total amount spent by customers), the amount paid to the company would remain the same. Oops, I now realize that while the total amount spent by customers would remain the same, the cost of producing the product goes up with every product sold. So if the businessman used this equation, he would be increasing the ratio of the amount of money made to the cost of production. In other words, xy = a + bx, where x = number of products sold, y = the price/unit sold, a = the total amount collected from the sale of the product and b = the cost of producing 1 unit.