Question

MODELING REAL LIFE
Use the Internet or another reference to find the populations and areas (in square miles) of India, China, Argentina, the United States, and Egypt. Round each population to the nearest million and each area to the nearest thousand square miles.
a. Write each population and area in scientific notation.
b. Use your answers to part(a) to find and order the population densities (people per square mile) of each country from least to greatest.

Answer 1

The following were found by doing a google search :
we write each population and area in scientific notation,
We know $1$ billion = ${10}^9$ and $1$ million = ${10}^6$ ,
a. In India : Population = $1.311$billion = $1.311\times {10}^9$
Area =$1.268$ million =$1.269\times {10}^6$
In China : Population =$1.371$ billion = $1.371\times {10}^9$
Area =$3.705$ million= $3.705\times {10}^6$
In Argentina : Population= $4.3$ million = $4.3\times {10}^7$
Area = $1.074$ million = $1.074\times {10}^6$
In United States : Population= $321$ million = $321\times {10}^8$
Area =$3.797$ million= $3.797\times {10}^6$
In Egypt: Population = $92$ million= $9.2\times {10}^7$
Area =$390,000$ = $3.9\times {10}^6$

Hence, In India : Population =$1.311\times {10}^9$, Area = $1.269\times {10}^6$

In China : Population = $1.371\times {10}^9$, Area = $3.705\times {10}^6$

In Argentina : Population = $4.3\times {10}^7$ , Area = $1.074\times {10}^6$

In United States : Population = $3.21\times {10}^8$, Area = $3.797\times {10}^6$

In Egypt: Population = $9.2\times {10}^7$, Area =$3.9\times {10}^6$

and The population densities are

India = $1.033\times {10}^3$

China = $3.7\times {10}^2$

Argentina =$4.0\times {10}^1$

United States =$8.45\times {10}^1$

and in Egypt = $2.36\times {10}^1$
Each country from least to greatest is: Egypt, Argentina, United States, China, India.