The budgeted overhead cost for the year is $1,260,000. the company has estimated that one-third of the budgeted overhead cost is incurred to support the firm's two partners, and two-thirds goes to support the staff accountants. the current audit bid for monoco industries requires $18,000 in direct partner professional labor, $30,000 in direct staff accountant professional labor, $5,000 in direct material. what is the overhead rate based on a single cost driver (rounded to the nearest percentage)?