John Tupper, D.D.S, opened an incorporated dental practice called John Tupper Professional Dentistry Corporation on January 1, 2020. During the first month of operations the following selected transactions occurred: 1. Performed services for patients who had dental plan insurance. At January 31, $600 of such services was earned but not yet billed to the insurance companies. 2 Utility expenses incurred but not paid prior to January 31 totalled $450. 3 4. 5. Purchased dental equipment on January 1 for $60,000, paying $20,000 in cash and signing a $40,000, 3-year note payable (interest, at 6% is paid each December 31). The equipment is being depreciated using the straight-line method. Management expects it to have a useful life of 15 years and a residual value of $6,000. Interest has not been recorded for the month. Purchased a 1-year malpractice insurance policy on January 1 for $18,000. The cost of the insurance policy was debited to the Prepaid Insurance account when purchased on January 1. Purchased $1,500 of dental supplies (recorded as increase to Supplies). On January 31 determined that $400 of supplies were on hand.