Acme Company's production budget for August is 18,100 units and includes the following component unit costs: direct materials, $8.0; direct labor, $10.5; variable overhead, $6.5. Budgeted fixed overhead is $38,000. Actual production in August was 19,872 units. Actual unit component costs incurred during August include direct materials, $9.00; direct labor, $10.00; variable overhead, $7.50. Actual fixed overhead was $40,100. The standard variable overhead rate per unit consists of $6.5 per machine hour and each unit is allowed a standard of 1 hour of machine time. During August, $149,040 of actual variable overhead cost was incurred for 21,600 machine hours Required: Calculate the variable overhead spending variance and the variable overhead efficiency variance. Note: Do not round intermediate calculations. Indicate the effect of each variance by selecting " F " for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance)