Koebel Corporation uses a job order cost system with manufacturing overhead applied to products on the basis of direct labor hours. For the upcoming year, Koebel Corporation estimated total manufacturing overhead cost at $$517,000$ and total direct labor hours of $51,700.$ Koebel Corporation started the year with no beginning balances in elther Work in Process Inventory or Finished Goods Inventory. During the year, actual manufacturing overhead incurred was $$509,500$ and $48,600$ direct labor hours were used.

Required:

a$.$ Calculate the predetermined overhead rate.

b$.$ Calculate how much manufacturing overhead will be applied to production.

c$.$ Is overhead over$-$ or underapplied? By how much?

d$.$ What account should be adjusted for over$-$ or underapplied overhead? Should the balance be increased or decreased?