P$18\mathrm{.}5($LO $3,4,5),$ E Mary 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 $$29,000$ in fixed costs to the $$270,000$ currently spent. In addition, Mary is proposing that a $5\%$ price decrease $($ $$40$ to $$38)$ will produce a $25\%$ increase in sales volume to $25,000$