Final answer:
In a perfectly competitive market, if Walter's costs are typical in the industry, new firms would enter the market for watches, the price would fall, and each individual firm in the market would produce fewer watches.
Step-by-step explanation:
In a perfectly competitive market, if Walter's costs are typical in the industry, we would expect that in the long run, new firms would enter the market for watches, the price would fall, and each individual firm in the market would produce fewer watches. This is because as new firms enter the market, the supply of watches increases, leading to a decrease in price. With more firms competing for customers, each individual firm produces fewer watches to maintain their market share.