In addition to other costs, Thornton Telephone Company planned to Incur $469,920 of fixed manufacturing overhead in making 356,000 telephones. Thornton actually produced 364,000 telephones, Incurring actual overhead costs of $462,920. Thornton 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 (l.e., zero varlance).) c. Determine the fixed cost volume variance and indicate whether it is favorable (F) or unfavorable (U). (Select "None" If there is no effect (.e., zero varlance).) a. : per unit b. Predetermined overhead rate Total fixed cost spending variance Total fixed cost volume variance c