Answer:
Dr Retained earnings  $6,200
Cr Dividends payable        $6,200
Explanation:
The shares entitled to dividends payment are those outstanding as at when dividends were declared,that is those shares in issue as at the date of dividend declaration,in essence only the outstanding shares of  12,400 are entitled to dividend payment of $0.50 per share.
The amount of dividend payment=$0.50*12,400=$6,200
The total dividends declared of $6,200 would be debited to retained earnings and credited to dividends payable until the payment date when the cash would be settled.