i attached answer, just need to fill red marked table,, what is the post ref,? i don't understand. please fill this

The Riley Company reports the following for the month of November DATE EXPLANATION UNITS 11/1 11/8 11/10 11/18 11/25 Inventory Purchase Sale Purchase Sale 300 300 200 50 300 UNIT COST OR UNIT SELLING PRICE $10 $11 $25 $12 S28 The Riley Company uses a perpetual inventory system. 1) Calculate the cost of the Ending Inventory at 11/30 and the Cost of Goods Sold for the month of November under the LIFO cost flow assumption. ENDING INVENTORY COST OF GOODS SOLD 2) Prepare the journal entry to record the sale on 11/25 assuming that the sale was on credit JOURNAL Post Ref. Date Description Debit Debit Credit Statement of Inventory Balance (LIFO) Date Opening Stock Units Price Amount Units 1-Nov 300 10 3000 Purchases Cost of Goods Sales Closing Stock Price Amount Units Price Amount Units Price Amount 300 10 3000 8-Nov 300 11 3300 300 300 10 11 3000 3300 10-Nov 200 11 2200 300 100 10 11 3000 1100 18-Nov 501 12 600 300 100 50 10 11 12 3000 1100 600 25-Nov 150 10 1500 50 100 150 12 11 10 600 1100 1500 1 Ending Inventory 1500 Cost of Goods sold 5400 2 Journal Entry of sale on 11/25 8400 Account Receivable Alc.....Dr. To Sales Alc 8400