Reamer Corporation uses a predetermined overhead rate based on machine$-$hours to apply manufacturing overhead to jobs. The Corporation has provided the following estimated costs for next year:Direct materialsDirect laborSales commissionsSalary of production supervisorIndirect materialsAdvertising expenseRent on factory equipment$ $1,000$$ $3,000$$ $4,000$$ $2\mathrm{.}000$S$400$$$800$$ $1,000$Reamer estimates that $500$ direct labor$-$hours and $1,000$ machine$-$hours will be worked during the year. The predetermined overhead rate per hour will be:$$6\mathrm{.}80/$ machine hour$$6\mathrm{.}00/$ machine hour $$3\mathrm{.}00/$ machine hour$$3\mathrm{.}40/$ machine hour