If you buy a $100 item at Walmart, what did Walmart pay for that item? Look at Walmart’s 2015 Income Statement (page 36 in the annual report, page 38 of the PDF document). It shows Cost of Sales of $365 billion on net sales of $482 billion, which is 76%. Thus on average, Walmart paid $76 for the item and sold it for $100. For your first posting, look up the income statement of some other retailer and do the same analysis.
Use the company’s actual income statement, from their annual report. DO NOT get data from an aggregator like Yahoo Finance, Nasdaq, Morningstar, etc.
Include a link to the income statement you are using, including page numbers, if applicable.