RTI Company's master budget calls for production and sale of 18,400 units for $86,480, variable costs of $33,120, and fixed costs of $20,400. During the most recent period, the company incurred $32,400 of variable costs to produce and sell 20,400 units for $85,400. During this same period, the company earned $25,400 of operating income. Required: 1. Determine the following for RTI Company: (Do not round intermediate calculations. Round your answers to the nearest whole dollar.) a. Flexible budget operating income. b. Flexible budget variance, in terms of contribution margin. Was this variance favorable or unfavorable? c. Flexible budget variance, in terms of operating income. Was this variance favorable or unfavorable? d. Sales volume variance, in terms of contribution margin. Was this variance favorable or unfavorable? e. Sales volume variance, in terms of operating income. Was this variance favorable or unfavorable