Diamond Advertising was established on June 1, 2019. The companys trial balance as of June 30, 2019, shows the following account balances:

Advertising revenue $18,000

Unearned revenue $42,000

Office equipment $20,000

Prepaid insurance $4,800

The following additional information was provided:

• Advertising services not yet billed at the end of June were $10,000.

• Prepaid six months advertising packages of $1,800 each were paid on June 1 and services for the month of June were carried out.

• Depreciation of office equipment was done at the rate of $400 per month.

• A two-year insurance policy was effective June 1.