Prepare general journal entries on December 31 to record the following unrelated year-end adjustments.

a. Estimated depreciation on equipment for the year, $4,500.

b. The Prepaid Insurance account has a $3,680 debit balance before adjustment. An examination of insurance policies shows $600 of insurance expired.

c. The Prepaid Insurance account has a $2,400 debit balance before adjustment. An examination of insurance policies shows $950 of unexpired insurance.

d. The company has three office employees who each earn $100 per day for a five-day workweek that ends on Friday. The employees were paid on Friday, December 26, and have worked full days on Monday, Tuesday, and Wednesday, December 29, 30, and 31.

e. On November 1, the company received 6 months' rent in advance from a tenant whose rent is $700 per month. The $4,200 was credited to the Unearned Rent account.

f. The company collects rent monthly from its tenants. One tenant whose rent is $1,000 per month has not paid his rent for December.