Conway Company manufactures three products as part of a joint process: A1, B1, and C1. Joint costs up to the split-off point total $24,000. The joint costs are allocated in proportion to their relative sales values. At the split-off point, product A1 can be sold for $30,000, product B1 can be sold for $50,000 and product C1 can be sold for $20,000. Product A1 can be processed further to make product A2, at an incremental cost of $18, 000.A2 can be sold for $54,000. Product B1 can be processed further to make product B2, at an incremental cost of $38,000. B2 can be sold for $85,000. Product C1 can be processed further to make product C2, at an incremental cost of $12,000. C2 can be sold for $34,000. Joint costs allocated to product B1 total: The net change in operating income resulting from a decision to manufacture product B2 a