You have been contracted by a local antique store to design an algorithm determining the total purchases and sales tax. According to the store owner, the user will need to see the subtotal, the sales tax amount, and the total purchase amount. A customer is purchasing four items from the antique store. Design an algorithm where the user will enter the price of each of the four items. The algorithm will determine the subtotal, the sales tax, and the total purchase amount. Assume the sales tax is 7%.