At the end of an advertising campaign, weekly sales declined according to the equation y 13.000(4 where x is the number of weeks after the end of the campaign a. Determine the sales at the end of the ad campaign b. Determine the sales 4 weeks after the end of the campaign c. Does this model indicate that sales will eventually reach 507 The sales at the end of the campaigh are 1 (Round to the nearest cent)