4. Darby Dairy has four product lines: Sour Cream, Ice Cream, Yogurt, and Butter. Information related to the company's four product lines is illustrated below for the month of June: Units sold Sour Cream 2,000 Ice Cream 500 Yogurt 400 Butter 200 Total 3,100 Revenue $10,000 $20,000 $10,000 $20,000 $60,000 Variable costs (6,000) 13,000 (4,200) (4,800) (28,000) Contribution Margin $4,000 $7,000 $5,800 $15,200 $32,000 Fixed costs (7,000) (2,000) (3,000) (7,000) (19,000) Net income (loss) $ (3,000) $ 5,000 $ 2,800 $ 8,200 $13,000 Darby is considering dropping the Sour Cream product line. If the Sour Cream line is eliminated, Darby would avoid 70% of the fixed costs attributable to the Sour Cream line. Prepare an incremental analysis to show the effect of dropping this product line. Based on your analysis, should the Sour Cream product line be retained or eliminated, and what is the amount of incremental net income or net loss that would result from eliminating the product line?