12. The Big Bear Lumber Company is trying to decide whether to sell or process further rough-sawn lumber. The joint cost of producing the available: rough-sawn lumber is $10,500. The following data are Incremental Cost to Process Lumber Type Number of Boards Selling Price per BoardFurther AtSplit-Off S 8 16 25 After Additional Processing $12 20 30 2,000 $7,000 500 1,000 a. What is the incremental effect, increase or (decrease), on operating income of processing the lumber further of each lumber type? b. Which sype of fumber shouald be proeseod frher