Whitlock Manufacturing uses a job costing accounting system for its production costs. The company uses a predetermined overhead rate based on direct materials costs to apply overhead to individual jobs. The company prepared an estimate of overhead costs at different volumes for the current year as follows:

Whitlock expects to spend $$400,000$ in direct materials costs over the entire year. The following information is for May, when Jobs WM$-52$ and WM$-53$ were completed:

Inventories, May $1$

Materials and supplies

Work in process $($Job WM$-52)$

Finished goods

Purchases of materials and supplies

Materials

Supplies

Materials and supplies requisitioned for production

Job WM$-52$

Job WM$-53$

Job WM$-54$

Supplies

Factory direct labor$-$hours $($DLH$)$

Job WM$-52$

Job WM$-53$

$900$ DLH

Job WM$-54$

$750$ DLH

$500$ DLH$$47,3008,0009,000$$$22,50010,500$$$12,0008,50011,500$$$32,000$

Required:

a$.$ Compute the predetermined overhead rate $($combined fixed and varlable$)$ to be used to apply overhead to individual Jobs during the year.