please help and explain!

Koebel Corp uses a job order costing system with manufacturing overhead applied to products on the basis of direct labor hours. For the upcoming year, Koebel Corp estimated total manufacturing overhead cost at $709,800 and total direct labor hours of 50,700. Koebel Corp started the year with no beginning balances in either Work in Process Inventory or Finished Goods Inventory. During the year actual manufacturing overhead incurred was $687,000 and 47,400 direct labor hours were used. (a) Calculate the predetermined overhead rate. Predetermined Overhead Rate per hour (b) Calculate how much manufacturing overhead will be applied to production Manufacturing Overhead Applied (c) is overhead over-or underapplied? By how much? (Input the amount as positive value.) Overhead (d) What account should be adjusted for over- or underapplied overhead? Should the balance be increased or decreased