Sandra Willis is the advertising manager for Bargain Shoe Store. She is currently working on a major promotional campaign. Her ideas include the installation of a new lighting system and increased display space that will add $$39,000$ in fixed costs to the $$423,000$ currently spent. In addition, Sandra is proposing that a $5\%$ price decrease $$60$ to $$57)$ will produce a $20\%$ increase in sales volume $(20,000$ to $24,000$