Use the chart below to answer the questions: Country
Population Area
(1997 estimate) (square km)
U. S.
272,648,000
9,364,520
Romania 22,609,000
237,391
Ghana
18,339,000
237,533
Which of these countries has the greatest population density? Which has the least?
Provide an explanation and proof for your answer to receive full credit.

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters