Montclair Company generates an average contribution margin ratio of 40% on sales of the companys products. The local store manager estimates that he can increase monthly sales volume by $45,000 by spending an additional $7,000 per month for direct mail advertising. What will the monthly increase in operating income be if the manager's estimate about the increased sales volume is accurate? Multiple Choice $11,000 $16,000 $18,000 $23,000