The supply curve S₁ for tomatoes at Pike Place Market shows how the quantity of tomatoes supplied varies with the price. As the price of tomatoes increases, producers supply greater quantities of tomatoes, creating an upward-sloping supply curve. At a price of $1 per pound, producers supply no tomatoes; at $2, $3, $4, and $5, respectively, producers supply 200, 400, 600, and 800 pounds of tomatoes.