Winton enterprises had the following events during 2007:

-issued 10,000 of common stock to stockholders

-purchased land for 6,000 cash

-services were provided to customers for 8,000 cash

-services were provided to customera for 5,000 on account

-company borrowed 8,000 from bank

-operating expenses of 6,000 were incurred and paid in cash

-interest of 500 was accrued on the bank loan

-a dividend of 2,000 was paid to the owners of Winton Enterprise

Assuming the company began operations in 2007, calculate the amount of retained earnings as of 12/31/2007

--The correct answer provided is 4,500. Please provide steps and explinations on how to calculate this number