Bluebird mfg. has received a special one-time order for 15,000 bird feeders at $3.60 per unit. bluebird currently produces and sells 75,000 units at $7.60 each. this level represents 80% of its capacity. production costs for these units are $4.40 per unit, which includes $2.55 variable cost and $1.85 fixed cost. if bluebird accepts this additional business, the effect on net income will be: