Willis Corporation manufactures industrial-sized gas furnaces and uses budgeted machine-hours to allocate variable manufacturing overhead. The following information pertains to the company's manufacturing overhead data: Budgeted output Budgeted machine-hours Budgeted variable manufacturing overhead costs for 30,000 units Actual output produced Actual machine-hours used Actual variable manufacturing overhead costs 30,000 units 10,000 hours $322,500 44,000 units 14,400 hours $484,000 18. What is the variable overhead rate variance? a. $11,000 favourable b. $13,611 unfavourable c. $13,611 favourable d. $19,600 favourable e. $19,600 unfavourable 19. What is the variable overhead efficiency variance? a. $8,600 favourable b. $8,600 unfavourable c. $141,900 favourable d. $141,900 unfavourable e. S11,000 unfavourable