Kirtland Corporation uses a periodic inventory system. At the end of the annual accounting period, December $31,$

the accounting records for the most popular item in inventory showed the following:

Required:

a$.$ Compute the amount of goods available for sale.

b$.$ & c$.$ Compute the amount of ending inventory and cost of goods sold at December $31,$ under Average cost,

First$-$in$,$ first$-$out, Last$-$in$,$ first$-$out and Specific identification inventory costing methods. For Specific identification,

assume that the first sale was selected two$-$fifths from the beginning inventory and three$-$fifths from the purchase

of January $30.$ Assume that the second sale was selected from the remainder of the beginning inventory, with the

balance from the purchase of May $1.$