Other data: 2018 2019 2020 Rent expense $10,000 $11,000 Food customers served 66.667 65,385 Food inventory at year-end $4,800 $5,000 $5,300 Employee meals $1,500 $1,550 "Include as part of employee benefits Determine the following for 2019 and 2020: a) Average food service check b) Food cost percentage c) Labor cost percentage d) Labor cost per customer served e) Operating efficiency ratio Profit margin