The static budget, at the beginning of the month, for Singleton Company follows: Static budget: Sales volume: 1,000 units: Sales price: S70 per unit Variable costs: $33 per unit; Fixed costs: S35.600 per month Operating income: $1,400 Actual results, at the end of the month, follows: Actual results: Sales volume: 980 units: Sales price: $74 per unit Variable costs: $35.50 per unit; Fixed costs: $34,300 per month Operating income: $3,430 Calculate the flexible budget variance for fixed costs. $0 $1,300 U $2,770 F $1,300 F