How do I prepare an incremental analysis of a special order???

Exercise 20-3 Leno Company manufactures toasters. For the first 8 months of 2014, the company reported the following operating results while operating at 75% of plant capacity; Sales (351,800 units) Cost of goods sold Gross profit Operating expenses Net income $4,378,900 2,608,000 1,770,900 839,200 $931,700 Cost of goods sold was 69% variable and 31% fixed; operating expenses were 74% variable and 26% fixed. In September, Leno Company receives a special order for 18,900 toasters at $8.0 each from Centro Company of Ciudad Juarez. Acceptance of the order would result in an additional $3,000 of shipping costs but no increase in fixed operating expenses