The retained earning in the beginning of 2013 will be calculated as under.
Given,
Ending retained earnings = $ 2,550
Income earned during the year = Revenue - Expenses
Income earned during the year = $ 2,800 - $ 1,500
Income earned during the year = $ 1,300
Dividends paid = $ 900
Ending retained earnings = Beginning retained earnings + Net Income - Dividends paid
$ 2,550 = Beginning retained earnings + $ 1,300 - $ 900
Beginning retained earnings = $ 2,550 - $ 400 = $ 2,150
Beginning retained earnings = $ 2,150