Turbo Shop uses job order costing to determine the cost of performing engine repair work. Estimated costs and expenses for the coming period are as follows:

Line Item Description Amount

Engine parts $$739,800$

Shop direct labor $540,000$

Shop and repair equipment depreciation $41,700$

Shop supervisor salaries $116,000$

Shop property taxes $21,100$

Shop supplies $16,200$

Advertising expense $14,800$

Administrative office salaries $63,600$

Administrative office depreciation expense $8,100$

Total costs and expenses $$1,561,300$

The average shop direct labor rate is $$18\mathrm{.}00$ per hour.

Determine the predetermined shop overhead rate per direct labor hour.