Perpetual inventory using weighted average

Beginning inventory, purchases, and sales for WCS $12$ are as follows:

Oct. $1$ Inventory $310$ units at $$9$

Oct. $13$ Sale $190$ units

Oct. $22$ Purchase $380$ units at $$11$

Oct. $29$ Sale $200$ units

a$.$ Assuming a perpetual inventory system and using the weighted average method, determine the weighted average unit cost after the October $22$ purchase. Round your answer to two decimal places.

$ per unit

b$.$ Assuming a perpetual inventory system and using the weighted average method, determine the cost of goods sold on October $29.$ Round your "average unit cost" to two decimal places.

$

c$.$ Assuming a perpetual inventory system and using the weighted average method, determine the inventory on October $31.$ Round your "average unit cost" to two decimal places.