The following is total monthly budgeted cost and activity information for the four activity centers in the billing department of Oregon Power Company: Cost Driver Activity Center Account inquiry Correspondence Account billing Bill verification Variable $80,852 $9,315 $144,000 $ 10,360 Fixed $152,000 $27,000 $77,000 $79,000 3,400 labor hours 2,700 letters 2,400,000 lines 18,500 accounts In September, actual costs and activity were as follows: Activity Center Account inquiry Correspondence Account billing Bill verification Total Costs $233,794 $36,343 $219,263 $90,197 Driver Amount 3,480 labor hours 2,740 letters 2,370,000 lines 18,400 accounts Required Compute the flexible-budget variances for the following two activity cost items (round all answers to the nearest dollar and enter favorable variances as positive numbers and unfavorable variances as negative numbers): Correspondence Account billing