Answer:
The year-end closing entries are as follows:
(a) Sales revenue A/c Dr. $839,807
 Interest revenue A/c Dr. $13,020
 To Income summary A/c $852,827
(To record close of revenue account)
(b) Income summary A/c Dr. $760,975
 To Cost of Goods Sold $534,832 
To Administrative Expenses $193,450
To Income Tax Expense $32,693 
(To record close of expenses account)
(c) Income summary a/c ($852,827 - $760,975) Dr. $91,852
To Retained earnings a/c $91,852 
(To record close of income summary a/c)
(d) Retained earnings a/c Dr. $19,345
To Dividend a/c $19,345
(To record dividend account)