Brief Exercise 9-7 (Algo) Retail inventory method; average cost [LO9-3] Kiddie World uses a periodic inventory system and the retall inventory method to estimate ending inventory and cost of goods sold. The following data are avallable at the end of the year: Estimate ending inventory and cost of goods sold (abterage cost). Note: Round ratio calculation to 2 decimal places (i.e., 0.1234 should be entered as 12.34%.)