PQR Ltd. had the following transactions in October 2023:

Date	Transaction
October 3	Purchased inventory for $25,000, paying $10,000 in cash and the rest on account.
October 7	Sold goods costing $12,000 for $18,000 on account.
October 13	Paid $1,500 for advertising expenses.
October 19	Collected $10,000 from customers on account.
October 25	Paid suppliers $15,000.
October 30	Declared and paid dividends of $2,500.

Requirements:

1. Journalize the transactions.
2. Post the journal entries to the general ledger.
3. Prepare a trial balance as of October 31, 2023.
4. Prepare an income statement for October 2023.
5. Analyze the impact of advertising expenses on sales and profitability.