Butterfly Corp. manufactures products M1 and M2 from a joint process, which also yields a by-product, B1. Butterfly accounts for the revenues from its by-product sales as other income. Additional information follows: M1 M2 B1 Total Units produced 22,500 13,500 9,000 45,000 Allocated joint costs ? ? ? $ 400,000 Sales value at split-off $ 420,000 $ 280,000 $ 100,000 $ 800,000