Answer:
The answer is: Manganese's operating income will increase by $26,250
Step-by-step explanation:
The total order is worth $45,000 (= 750 frames x $60 per frame).
Manganese will spend $20 in direct materials and $5 in variable overhead per frame, which adds up to $25 cost per frame.
Since Manganese will have to pay their workers salary with or without this special order, we can't consider additional labor costs associated with this special order.
So the total revenue is $45,000 and the total additional costs are $18,750.
So the operating income will increase by $26,250 which is the difference between total revenue and total costs (= $45,000 - $18,750)