// Output file corresponding to "order.dat":
//
Customer Invoice:

SKU    Units   Unit Price     Extended
--------------------------------------
4331       3         9.97        29.91
7335       1         2.23         2.23
7338       2         1.00         2.00
7339      10         0.75         7.50
7350       6         2.98        17.88
3110       1        19.99        19.99
4132       1         5.67         5.67
5001       1         7.95         7.95
1234       4         1.75         7.00
--------------------------------------
              Total Price:      100.13
               Sales Tax :        4.51
              Grand Total:      104.64
             ------------------------- 

Average cost per unit:      3.45