Cost flow assumptions$-$FIFO, LIFO, and weighted average using a periodic system The following data are available for Sellco for the fiscal year ended on January $31,2023$ :

Required:

a$.$ Calculate cost of goods sold and ending inventory under the following cost flow assumptions $($using a periodic inventory system$)$:

FIFO.

LIFO.

Weighted average. Round the unit cost answer to two decimal places and ending inventory to the nearest $$10.$

b$.$ Assume that net income using the weighted$-$average cost flow assumption is $$80,000.$ Calculate net income under FIFO and LIFO.