Payton Industries Had the Following Purchases as of September 30,20X3

Payton Industries had the following purchases as of September 30,20X3.
$$\begin{array}{l}\begin{array} { l } \text { September } 3 \text { order of } 400 \text { unit } @\$ 10.50 \\\text { September 8 order of } 100 \text { unit } @ \$ 11.00 \\\text { September } 19 \text { order of } 200 \text { unite } @\$ 11.50\end{array}\begin{array} { l } \\\$ 4,204 \\1,100 \\2,300 \\\$ 7,600\\\end{array}\end{array}$$ On September 20,20X3,the company sold 240 units at $16.00 per unit.On September 30,20X3,a competitor announced a new model which resulted in the cost of Payton's inventory dropping to the new replacement cost,which was $10.75 per unit.The net realizable value also declined.Payton Industries uses a perpetual inventory system.
1.What is the balance in the inventory account on September 30,20X3,if Payton Industries uses:
a.FIFO?
b.LIFO?
2.What journal entry is necessary on September 30,20X3,if Payton Industries uses lower-of-cost-or-market,where cost is defined as:
a.FIFO?
b.LIFO?