Can you calculate with method: " Average" please? And explain the calculation.

Q1 Q2 Opening inventories on March 1, 2018 March 4: Sale March 12: Purchase March 19: sale: March 25: Purchased March 29th: sale Quantity $ Per unit 500 50 400 650 51 450 600 52 200 Calculate closing balance for inventories of Division C on March 31, 2018. Division C specifies the standard for inventories reserve (i.e. ending inventories) is 550 kg. Prepare the financial report to interpret and inform Manager about problems of the exceeding inventories