(Adjusting Entries) Karen Weller, D.D.S., opened a dental practice on January 1, 2005. During the first month of operations the following transactions occurred.

1. Performed services for patients who had dental plan insurance. At January 31, $750 of such services was earned but not yet billed to the insurance companies.

2. Utility expenses incurred but not paid prior to January 31 totaled $520.

3. Purchased dental equipment on January 1 for $80,000, paying $20,000 in cash and signing a $60,000, 3-year note payable. The equipment depreciates $400 per month. Interest is $500 per month.

4. Purchased a one-year malpractice insurance policy on January 1 for $12,000.

5. Purchased $1,600 of dental supplies. On January 31, determined that $500 of supplies were on hand. Prepare the adjusting entries on January 31. Account titles are: Accumulated Depreciation—Dental Equipment; Depreciation Expense; Service Revenue; Accounts Receivable; Insurance Expense; Interest Expense; Interest Payable; Prepaid Insurance; Supplies; Supplies Expense; Utilities Expense; and Utilities Payable.