Sipple Furniture's master budget for the year includes $341,400 for fixed supervisory salaries. Practical capacity, which is used to s the fixed overhead allocation rate, is 690 units per month. Supervisory salaries are expected to be incurred uniformly throughout th year. During August, the company produced 440 units, incurred production supervisory salaries of $29.950, and reported underapplied fixed overhead of $23,500 for supervisory salaries. What is Sipple Furniture's supervisory salaries spending (budget) varlance for August? Is this variance favorable (F) or unfavorable (U)? (Leave no cell blank; if there is no effect enter "O" ond selec "None" from dropdown.)