The following standards for variable manufacturing overhead have been established for Carla Vista, Inc. a manufacturer of reproduction vintage hats. 2.50 hours Standard hours per unit Standard variable overhead rate $12.80 per direct labor hour The following data pertain to operations for the month of July. Actual direct labor hours 9,200 Actual total variable overhead cost $93.000 Actual production 3,800 units Calculate the variable overhead spending variance and the variable overhead efficiency variance for July and indicate whether the variances are favorable or unfavorable. Variable overhead spending variance $ Variable overhead efficiency variance $