Final answer:
The plantwide predetermined overhead rate for Mickley Company cannot be determined based on the information provided.
Step-by-step explanation:
The plantwide predetermined overhead rate for Mickley Company can be determined using the information provided. The company's marginal cost of labor is given as $1 per hour. To calculate the predetermined overhead rate, we need to divide the total overhead costs by the total direct labor-hours. However, the total overhead costs are not given in the information, so we cannot determine the plantwide predetermined overhead rate for Mickley Company.