Laval produces lamps and home lighting fixtures. Its most popular product is a brushed aluminum desk lamp. This lamp is made from components shaped in the fabricating department and assembled in the assembly department. Information related to the $25,000$ desk lamps produced annually follows.

Direct materials $ $265,000$

Direct labor

Fabricating department $(9,000$ DLH $\backslash$times $$27$ per DLH$)$ $ $243,000$

Assembly department $(16,400$ DLH $\backslash$times $$24$ per DLH$)$ $ $393,600$

Machine hours

Fabricating department $15,300$ MH

Assembly department $21,050$ MH

Expected overhead cost and related data for the two production departments follow.

Fabricating Assembly

Direct labor hours $120,000$ DLH $315,000$ DLH

Machine hours $157,000$ MH $123,000$ MH

Overhead cost $ $390,000$ $ $410,000$

Required

$1.$ Determine the plantwide overhead rate for Laval using direct labor hours as a base.

$2.$ Determine the total manufacturing cost per unit for the aluminum desk lamp using the plantwide overhead rate.

$3.$ Compute departmental overhead rates based on machine hours in the fabricating department and direct labor hours in the assembly department.

$4.$ Use departmental overhead rates from requirement $3$ to determine the total manufacturing cost per unit for the aluminum desk lamps.