When a walk-in clinic spent $5,000 a year on newspaper advertising, it saw 5,000 patients a year. When it increased its annual advertising expenditure to $7,500 per year, it saw 10,000 patients a year a. What is the change in advertising expenditures? b.What is the change in patient visits? c. What is the advertising elasticity of demand? d. Do you think the increase in advertising expenditures was worthwhile and why?