A company's flexible budget for 56,000 units of production showed variable overhead costs of $106,400 and fixed overhead costs of $72,000. The company incurred overhead costs of $161,920 while operating at a volume of 48,000 units. The total controllable cost variance is: $1,280 favorable. $1,280 unfavorable. $16,480 favorable. $16,480 unfavorable. $18,480 favorable.