A. Using these data, state assumptions about functional dependencies among the columns of data. Justify your assumptions on the basis of these sample data and also on the basis of what you know about retail sales.

Given your assumptions in part A, comment on the appropriateness of the following (Bolded are primary key):

1. CUSTOMER (LastName, FirstName, Phone, EmailAddress, InvoiceDate, InvoiceItem,Price, Tax, Total)

2. CUSTOMER (LastName, FirstName, Phone, EmailAddress, InoviceDate, InvoiceItem, Price, Tax, Total)

3. CUSTOMER (LastName, FirstName, Phone, EmailAddress, InvoiceDate, InvoiceItem, Price, Tax, Total)

4. CUSTOMER (LastName, FirstName, Phone, EmailAddress, InvoiceDate, InvoiceItem, Price, Tax, Total)

5. CUSTOMER (LastName, FirstName, Phone, EmailAddress, InvoiceDate, InvoiceItem, Price, Tax, Total)

LastName	FirstName	Phone	InvoiceDate	InvoiceItem	Price	Tax	Total
Shire	Robert	206-524-2433	14-Dec-17	Antique Desk	3,000.00	249.00	3249.00
Shire	Robert	206-524-2433	14-Dec-17	Antique Desk Chair	500.00	41.50	541.50
Goodyear	Katherine	206-524-3544	15-Dec-17	Dining Table Linens	1,000.00	83.00	1083.00
Bancroft	Chris	425-635-9788	15-Dec-17	Candles	45.00	3.74	48.74