Landen corporation uses a job order costing system

Landen Corporation uses a job-order costing system. At the beginning of the year, the company made the following estimates:
Direct labor-hours required to support estimated production . . . . . . . . . . . 140,000
Machine-hours required to support estimated production . . . . . . . . . . . . . . . 70,000
Fixed manufacturing overhead cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $784,000
Variable manufacturing overhead cost per direct labor-hour . . . . . . . . . . . . . $2.00
Variable manufacturing overhead cost per machine-hour . . . . . . . . . . . . . . . . $4.00
During the year, Job 550 was started and completed. The following information is available with respect to this job:
Direct materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $175
Direct labor cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $225
Direct labor-hours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Machine-hours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Required:
1. Assume that Landen has historically used a plant wide predetermined overhead rate with direct labor-hours as the allocation base. Under this approach:
a. Compute the plant wide predetermined overhead rate.
b. Compute the total manufacturing cost of Job 550.
c. If Landen uses a markup percentage of 200% of its total manufacturing cost, what selling price would it establish for Job 550?
2. Assume that Landen's controller believes that machine-hours is a better allocation base than direct labor-hours. Under this approach:
a. Compute the plant wide predetermined overhead rate.
b. Compute the total manufacturing cost of Job 550.
c. If Landen uses a markup percentage of 200% of its total manufacturing cost, what selling price would it establish for Job 550?
3. Assume that Landen's controller is right about machine-hours being a more accurate overhead cost allocation base than direct labor-hours. If the company continues to use direct labor-hours as its only overhead cost allocation base what implications does this have for pricing jobs such as Job 550?