The following is total monthly budgeted cost and activity information for the four activity centers in the billing department of Oregon Power Company: Variable Fixed Cost Driver $73,792 3,200 labor hours Activity Center Statement inquiry Correspondence Account billing Payment verification $153,000 $20,000 2,800 letters $9,940 $144,000 $87,000 2,400,000 lines $9,435 $78,000 18,500 accounts In September, actual total costs and activity were as follows: Activity Center Statement inquiry Correspondence Account billing Payment verification Total Costs $224,907 $28,741 $227,948 Driver Amount 3,160 labor hours 2,660 letters 2,350,000 lines $87,297 18,450 accounts Required Compute the flexible-budget variances for the following two activity cost items (round unit costs to two decimal places and enter favorable variances as positive numbers and unfavorable variances as negative numbers): Account billing Correspondence