The solution is to apply overhead using a predetermined overhead rate based on a relevant basis of production activity. Based on actual overhead incurred and using batches of product TC-1 as the activity base, the overhead rate is $16,000 per batch [($105,000 + $153,000 + $97,000 + $125,000) ÷ 30]. Another approach would be to use direct labor cost as the relevant basis to apply overhead on a predetermined basis. For example, a rate of 133 1/3% of direct labor cost ($480,000 ÷ $360,000) could be used. Either approach will provide the same result