Basic accounting: using the Perpetual Accounting in weighted Average method

Any notes are appreciated.

Perpetual Inventory Using Weighted Average

Beginning inventory, purchases, and sales for JWWZ9 are as follows:

Jan.1Inventory300units at $8

Jan.13Sale175 units at

Jan.22 Purchase375 units at $10

Jan.29 Sale280 units

1.Determine average unit cost after Jan.22 purchase?

2.Determine the cost of goods on Jan.29? (round average unit cost)

3.Determine inventory on Jan.31? (round average unit cost)