Can you help me, please?

Show me the formula please

Dymac Appliances uses the periodic inventory system. Details regarding the inventory of appliances at January 1, purchases invoices during the next 12 months, and the inventory count at December 31 are summarized as follows: Instructions Determine the cost of the inventory on December 31 by the first-in, first-out method. Present dat: in columnar form, using the following headings: \begin{tabular}{l} Weighted Average \\ \hline \\ \hline \end{tabular} FIFO first units purchased are the first sold, start counting at the end