In its first month of operations, Literacy for the Illiterate opened a new bookstore and bought merchandise in the following order: $(1)300$ units at $$7$ on January $1,(2)450$ units at $$8$ on January $8,$ and $(3)750$ units at $$9$ on January $29.$

a$.$ Assuming $900$ units are on hand at the end of the month, calculate the cost of goods available for sale, ending inventory, and cost of goods sold under FIFO. Assume a periodic inventory system is used. $($Round "Cost per Unit" to $2$ decimal places.$)$

b$.$ Assuming $900$ units are on hand at the end of the month, calculate the cost of goods available for sale, ending inventory, and cost of goods sold under LIFO. Assume a periodic inventory system is used. $($Round "Cost per Unit" to $2$ decimal places.$)$

c$.$ Assuming $900$ units are on hand at the end of the month, calculate the cost of goods available for sale, ending inventory, and cost of goods sold under Weighted Average Cost. Assume a periodic inventory system is used. $($Round "Cost per Unit" to $2$ decimal places.$)$