Final answer:
The operating expenses that should be revealed on XYZ's income statement, after adding the overlooked sales commissions to the period costs, amount to $455,000.
Step-by-step explanation:
The student asked for the correct amount of operating expenses that XYZ's income statement should reveal given the provided costs information. The company computed total product costs of $567,000, total period costs of $420,000, and there were overlooked sales commissions of $35,000. To find the operating expenses, we add the total period costs and the overlooked sales commissions, which gives us $420,000 + $35,000 = $455,000.