Final answer:
The plantwide predetermined overhead rate for Mickley Company cannot be determined based on the given information.
Step-by-step explanation:
The plantwide predetermined overhead rate for Mickley Company can be calculated by dividing the total estimated overhead costs by the total estimated direct labor-hours. According to the information provided, there is no direct mention of the total estimated overhead costs or direct labor-hours. Therefore, it is not possible to determine the plantwide predetermined overhead rate based on the given information.