less company uses a predetermined overhead rate based on machine hours to apply manufacturing overhead to jobs the company has provided the following estimated costs for next year: direct materials $$10,000$direct labor $30,000$sales commissions $40,000$salary of production supervisor $50,000$ indirect materials $4,000$as wedding expense $8,00$rent on factory equipment $10,000$kelsi estimated that $5,00$ direct labor hours and $10,000$ machine hours will be worked during the year the predetermined overhead rate will be a$.$ $$4\mathrm{.}20$ b$.$ $$8\mathrm{.}20$ c$$3\mathrm{.}40$ or de $$6\mathrm{.}40$