A flexible budget provides favorable operating results. is based on the budgeted level of output. is developed at the end of the period. is another name for management by exception. An unfavorable variance indicates that actual costs are less than budgeted costs. actual revenues exceed budgeted revenues. the actual amount decreased operating income relative to the budgeted amount. All of the above Which of the following statements is true about overhead cost variance analysis using activity-based costing? Overhead cost variances are calculated for output-unit level costs only. Overhead cost variances are calculated for variable manufacturing overhead costs only. A four-variance analysis can be conducted. Activity-based costing uses input measures for all activities, resulting in the inability to do flexible budgets needed for variance analysis