At January 1, 2020, Betty DeRose, Inc. reported work in process totaling $18,670. This balance was made up of three jobs having the following costs:  Job #171 Job #236 Job #412 total cost at Jan. 1, 2020 ..... $4,390 $6,370 $7,910 During 2020, Betty DeRose reported the following transactions: a. Direct materials used were: Job #171, $6,700; Job #236, $4,100; and Job #412, $3,900. b. Direct labor incurred was: Job #171, $5,000; Job #236, $2,800; and Job #412, $3,000. c. Overhead was applied to jobs at a rate of 85% of direct materials used. d. Job #171, which consisted of 100 units, was completed and transferred to the finished goods warehouse. e. Job #412, which consisted of 250 units, was completed and transferred to the finished goods warehouse. f. 40 units from Job #171 were sold and shipped to the customer; the 40 units were sold at a total selling price of $12,000. g. The actual overhead cost incurred during 2020 amounted to $10,000. Calculate Betty's work in process inventory balance at December 31, 2020.