The following is monthly budgeted cost and activity information for two activities in the purchasing department of X Company: Activity Supplier relations Invoicing Variable Costs Fixed Costs $5,000 $16,200 $12,600 $24,400 Cost Driver 200 suppliers 840 invoices In November, actual costs and activity were as follows: Activity Supplier relations Invoicing Total Costs $18,965 $36,806 Driver Amount 133 suppliers 820 invoices What was the flexible budget variance for the invoicing activity for November (assume that favorable variances are positive numbers and unfavorable variances are negative numbers)