Question 985672
{{{SquareMile = (1Mile) * (1Mile)}}}
{{{SquareMile = (1Mile)(5280ft/Mile) * (1Mile)(5280ft/Mile)}}}
{{{SquareMile = 5280^2 (ft)^2}}}
{{{SquareMile = 27878400}}} square feet

Now how many square feet are in NYC?

{{{NYCAreaInSquareFeet = 305 (squareMiles)* 27878400 (SquareFeet/SquareMile)}}}{{{NYCAreaInSquareFeet = 8502912000}}}

Now cram all the world's population into NYC? What do you get (besides a movie premise for Escape from NY?)

{{{(WorldsPopulation)/ (NYCAreaInSquareFeet) = (AreaPerperson)}}}
{{{(6700000000 / 8502912000) = (AreaPerperson)}}}
{{{0.787965346 = (AreaPerperson)}}}
{{{0.8}}} square feet per person. 

I hope you like your neighbors within reach!