areaMetro:=21910
areaUrban:=2392
areaCity:=170

area:={areaMetro, areaUrban, areaCity}

populationMetro:=2810000
populationUrban:=2150000
populationCity:=319000

population:={populationMetro, populationUrban, populationCity}

powerPerPerson:=3

sunPerSquareKilometer=1*1000^2

sun=area*sunPerSquareKilometer

ac=population*powerPerPerson

N[ac/sun]