Security Technology Inc. (STI) is a manufacturer of an electronic control system used in the manufacture of certain special-duty auto transmissions used primarily for police and military applications. The part sells for $42 per unit and had sales of 24,650 units in the current year, 2015. STI has no inventory on hand at the beginning of 2015 and is projecting sales of 27,950 units in 2016. STI is planning the same production level for 2016 as in 2015, 26,300 units. The variable manufacturing costs for STI are $13 and the variable selling costs are only $0.40 per unit. The fixed manufacturing costs are $184,100 per year and the fixed selling costs are $630 per year. Prepare a reconciliation and explanation of the difference each year in the operating income resulting from the full- and variable-costing methods. (Negative amounts should be indicated by a minus sign. Do not round intermediate calculations. Round your "Fixed overhead rate" answers to 2 decimal places, and other final answers to nearest whole dollar amount.)