Shamrock, Inc. reported these income statement data for a 2-year period 2017 2016 Sales revenue Beginning inventory Cost of goods purchased Cost of goods available for sale $250,200 41,090 197,330 238,420 54,360 184,060 $66,140 $203,070 30,480 156,380 186,860 41,090 145,770 $57,300 Ending inventory Cost of goods sold Gross profit Shamrock, Inc. uses a periodic inventory system. The inventories at January 1, 2016, and December 31, 2017, are correct. However, the ending inventory at December 31, 2016, is overstated by $8,460