Derived PreferredCustomer ClassA retail store has a preferred customer plan where customer...

Derived PreferredCustomer Class

A retail store has a preferred customer plan where customers may earn discounts on all their purchases. The amount of a customer’s discount is determined by the amount of the customer’s cumulative purchases in the store.

• When a preferred customer spends $500, he or she gets a 5% discount on all future purchases.

• When a preferred customer spends $1000, he or she gets a 6% discount on all future purchases.

• When a preferred customer spends $1500, he or she gets a 7% discount on all future purchases.

• When a preferred customer spends $2000 or more, he or she gets a 10% discount on all future purchases.

Open the Customer Information project that you modified in Programming Challenge 11. Design a new class named PreferredCustomer, which is derived from the Customer class. ThePreferredCustomer class should have the following properties:

• PurchasfiBAmount (decimal)

• DiscountLevel (single)

Modify the application’s form so it allows you to store data in each property of a PreferredCustomer object. Add the object to a collection, using the customer number as a key. Allow the user to look up a preferred customer by the customer number, edit the customer data, and remove a customer from the collection.