The following is data related to the purchases and sales of a company for the year 1440 AH in 1/1 balance of 500 units at a cost of 40 riyals per unit

in 1/15 Purchase of 600 units at a price of 50 riyals per unit

in 5/20 Purchase of 800 units at a price of 60 riyals per unit

in 2/9 Purchase400 units at a price of 55 riyals per unit

noting that the establishment sold during the period 1420 units at a price of 70 riyals per unit

what is required is to determine the value of the stock at the end of the period according to the following methods:

1. FIFO

2. LIFO

3. Weighted average method