In addition to other costs, Gibson Telephone Company planned to incur $462,840 of fixed manufacturing overhead in making 348,000 telephones. Gibson actually produced 356,000 telephones, incurring actual overhead costs of $456,840. Gibson establishes its predetermined overhead rate based on the planned volume of production (expected number of telephones). Required: a. Calculate the predetermined overhead rate. (Round your answer to 2 decimal places.) b. Determine the fixed cost spending variance and indicate whether it is favorable (F) or unfavorable (U). (Select "None" if there is no effect (i.e., zero variance).) c. Determine the fixed cost volume variance and indicate whether it is favorable (F) or unfavorable (U). (Select "None" if there is no effect (i.e., zero variance).) per unit b. c. Predetermined overhead rate Total fixed cost spending variance Total fixed cost volume variance