Hart Labs, Inc. provides mad cow disease testing for both state and federal governmental agricultural agencies. Because the company's customers are governmental agencies, prices are strictly regulated. Therefore, Hart Labs must constantly monitor and control its testing costs. Shown below are the standard costs for a typical test. Direct materials (2 test tubes @ $1.46 per tube) $2.92 Direct labor (1 hour @ $24 per hour) 24.00 Variable overhead (1 hour @ $6.00 per hour) Fixed overhead (1 hour @ $10.00 per hour) Total standard cost per test $42.92 6.00 10.00 The lab does not maintain an inventory of test tubes. Therefore, the tubes purchased each month are used that month. Actual activity for the month of November 2017, when 1,475 tests were conducted, resulted in the following: Direct materials (3,050 test tubes) $4,270 Direct labor (1,550 hours) 35,650 Variable overhead 7,400 Fixed overhead 15,000 Monthly budgeted fixed overhead is $14,000. Revenues for the month were $75,000, and selling and administrative expenses were $5,000. Compute the overhead controllable variance and the overhead volume variance. Overhead controllable variance $ Overhead volume variance