Rockville Enterprises manufactures woodworking equipment and is incorporated and based in Evansville, Indiana. All of its real property is in Indiana. Rockville Enterprises employs a large sales force that travels throughout the United States.

Determine whether each of the following is a Protected or Not Protected activity in nondomiciliary states under Public Law 86-272:

1. Rockville Enterprises advertises in Wisconsin using television, radio, and newspapers.
2. Rockville Enterprises's employees in Illinois check the credit of potential customers.
3. Rockville Enterprises maintains a booth at an industry trade show in Arizona for 10 days.
4. Sales representatives check the inventory of a Tennessee customer to make sure it has enough stock and that the stock is properly displayed.
5. Rockville Enterprises holds a management seminar executive retreat for corporate executives over four days in Florida.
6. Sales representatives supervise the repossession of inventory from a customer in Maine that is not making payments on time.
7. Rockville Enterprises provides automobiles to Idaho and Montana sales representatives.
8. An Alabama sales representative accepts a customer deposit on a large order.
9. Colorado sales reps carry display racks and promotional materials that they place in customers' retail stores without charge.