Final answer:
The estimated manufacturing overhead cost for the finishing department cannot be computed due to missing information.
Step-by-step explanation:
To compute the estimated manufacturing overhead cost for the finishing department, we need to multiply the overhead rate per machine hour by the total machine hours used in the department. In this case, the overhead rate is $3.20 per machine hour. Unfortunately, the question does not provide the total machine hours used in the finishing department, so we cannot compute the estimated manufacturing overhead cost.