A company expects next year's overhead costs to be $360,000. During this time, the company also expects to produce 1,800,000 units, have 200,000 total direct labor hours, and 720,000 total machine hours. Make the following independent calculations. Show your work. a. Compute a plantwide overhead rate using units of production as the allocation base. b. Compute a plantwide overhead rate using direct labor hours as the allocation base. c. Compute a plantwide overhead rate using machine hours as the allocation base