TB Problem Qu. 5-239 (Algo) Shelhorse Corporation produces and... Shelhorse Corporation produces and sells a single product. Data concerning that product oppear below: Fixed expenses are $354,000 per month. The company is currently selling 4,900 units per month. Required; The marketing manager believes that a $23.000 increase in the monthly advertising budget would result in a 170 unit increase in monthly sales. What should be the overall effect on the company's monthly not operating income of this change