Answer:
Ending inventory value is $762 (100 units at $5.50 each, i.e. $550 + 40 units at $5.30 each, i.e. $212).
Step-by-step explanation:
The FIFO inventory system assumes that the units bought first will be utilized first. It is called First-in, First-out.
The implication is that for the 140 units ending inventory for January 2013, the value will be split between the purchases on January 28 and January 15. Therefore, the first 100 units from the 140 are costed at the purchase price of $5.50 per unit while the remaining 40 units are costed at the purchase price of $5.30 per unit.
There are other methods of valuing inventory, including LIFO (Last in, First Out), Weighted Average Method, e.t.c. which are not discussed here.