During the course of your examination of the financial statements of Trojan Corporation for the year ended December 31, 2021, you come across several items needing further consideration. Currently, net income is $86,000.

1. An insurance policy covering 12 months was purchased on October 1, 2021, for $15,600. The entire amount was debited to Prepaid Insurance and no adjusting entry was made for this item in 2021.

2. During 2021, the company received a $2,600 cash advance from a customer for services to be performed in 2022. The $2,600 was incorrectly credited to Service Revenue.

3. There were no supplies listed in the balance sheet under assets. However, you discover that supplies costing $2,050 were on hand at December 31, 2021.

4. Trojan borrowed $56,000 from a local bank on September 1, 2021. Principal and interest at 12% will be paid on August 31, 2022. No accrual was made for interest in 2021.