Final answer:
Marino Corporation's journal entry for the sale of security Z would include a debit to cash for $34,000, a credit to trading securities for $32,000, and a credit to gains on sale of securities for $2,000.
Step-by-step explanation:
The sale of security Z by Marino Corporation would require an accounting journal entry that reflects the sale price, the cost of security Z, and the resulting gain. Since Marino bought the security at a cost of $32,000 and sold it for $34,000, the company realized a gain of $2,000.
The entry would debit cash for the sale proceeds of $34,000, credit trading securities for the original cost of $32,000, and credit gains on sale of securities for the $2,000 gain. The balances for securities X and Y would remain unchanged, as the market values at December 31, 2009, are the same as the previous year and no other transactions occurred.