Abbott has a standard variable overhead rate of $4.80 per machine hour, and each unit produced has a standard time allowed of 2.80 hours. The company's static budget was based on 46,000 units. Actual results for the year follow. Actual units produced: 42,000 Actual machine hours worked: 110,000 Actual variable overhead incurred: $510,000 Required information Abbott's variable-overhead spending variance is: $18,000 favorable. $18,000 unfavorable. $36,480 favorable. $36,480 unfavorable. None of these.