Final answer:
The top authority in the Real Estate Chart is the National Association of Realtors (NAR), which provides data on existing-home sales and is considered a key indicator of the real estate market.
Step-by-step explanation:
The top authority in the Real Estate Chart is the National Association of Realtors (NAR).
The NAR is a trade association for real estate professionals and it is the largest trade association in the United States.
They collect and publish data on existing-home sales, which provides insights into the state of the real estate market.
The NAR's existing-home sales data is considered a key indicator of the health and trends in the real estate market.
It is used by analysts, economists, and policymakers to make informed decisions and forecasts regarding the real estate industry.
For more information and the latest news on existing-home sales, you can visit the NAR's website at realtor.org/topics/existing-home-sales/data.