A Public Accounting Firm Employs 10 Full-Time Professionals Who Provide

A public accounting firm employs 10 full-time professionals who provide services to clients.All professional labour compensation is traced directly to clients on a per professional labour-hour basis.Any other costs are included in a single indirect-cost pool (same as overhead)and allocated to individual clients according to billable professional labour-hours.
Operating costs and data for the year included the following:
$\begin{array}{lrr}& \text { Estimated } & \text { Actual } \\\text { Overhead (indirect) costs } & \$ 1,000,000 & \$ 1,200,000 \\\text { Number of billable professional labour-hours } & 40,000 & 50,000 \\\text { Total professional compensation } & 750,000 & 750,000\end{array}$
Required:
a. By how much, if any, was the overhead cost underapplied or overapplied?
b. Prepare a summary journal entry to close any underapplied or overapplied overhead cost to a Cost of Services Provided account.
c. Explain qualitatively and quantitatively (in as much detail as possible) the source(s) of any underapplied or overapplied overhead cost.