A nationwide furniture company wants to survey their customers to determine whether or not they are providing quality customer service across the United States. They have 140 stores with an average of about 3,000 customers each per month. Which survey group would produce a valid sample?

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?