Prepare the adjusting entries at March 31, assuming that adjusting entries are made quarterly. Additional accounts are Depreciation Expense, Insurance Expense, Interest Payable, and Supplies Expense. (Omit explanations.) E3-6 (L03) (Adjusting Entries) Karen Weller, D.D.S., opened a dental practice on January 1, 2017. 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 performed 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. Instructions Prepare the adjusting entries on January 31. (Omit explanations.) Account titles are Accumulated Depreciation-Equipment, Depreciation Expense, Service Revenue, Accounts Receivable, Insurance Expense, Interest Expense, Interest Payable, Prepaid Insurance, Supplies, Supplies Expense, Utilities Expenses, and Accounts Payable