22. Robert Company, which applies overhead to production on the basis of machine hours, reported the following data for the period just ended: Actual units produced: 12,000 Actual variable overhead incurred: $77,700 Actual machine hours worked: 18,800 Standard variable overhead cost per machine hour: $4.50 If Robert estimates 1.5 hours to manufacture a completed unit, the company's variable- overhead spending variance is: $3,600 favorable. $3,600 unfavorable. $6,900 favorable. $6,900 unfavorable. some other amount not listed above. wpowe