The supply curve show how the quantity of a good offered for sale changes as the price of the good changes. The supply curve is upward sloping;the higher the price,the more firms are able and willing to produce and sell. If production costs fall,firms can produce the same quantity at a lower price or a larger quantity at the same price.The supply curve then shifts to the right. The supply curve show how the quantity of a good offered for sale changes as the price of the good changes. The supply curve is upward sloping; the higher the price, the more firms are able and willing to produce and sell. If production costs fall, firms can produce the same quantity at a lower price or a larger quantity at the same price. The supply curve then shifts to the right