## Chemistry: Molecular Approach (4th Edition)

$\underline{\text{42}\text{.15}%}$
Convert $\text{acres}$to $\text{f}{{\text{t}}^{\text{2}}}$ as follows: \begin{align} & 1\ \text{acre}=\text{43,560}\ \text{f}{{\text{t}}^{2}} \\ & \text{954}\ \text{million acres}=\left( 954\times {{10}^{6}} \right)\left( \text{43,560}\ \text{f}{{\text{t}}^{2}} \right) \end{align} Convert $\text{m}{{\text{i}}^{2}}$to $\text{f}{{\text{t}}^{\text{2}}}$ as follows: \begin{align} & 1\ \text{mi}=\text{5280}\ \text{ft} \\ & 1\text{ m}{{\text{i}}^{2}}=\left( 1\ \text{m}{{\text{i}}^{2}} \right)\left( 1\ \text{m}{{\text{i}}^{2}} \right) \\ & =\left( \text{5280}\ \text{ft} \right)\left( \text{5280}\ \text{ft} \right) \\ & =27,878,400\ \text{f}{{\text{t}}^{2}} \end{align} Calculate the total area in $\text{m}{{\text{i}}^{2}}$as follows: $\left( 954\times {{10}^{6}} \right)\left( 43,560\ \text{f}{{\text{t}}^{2}} \right)\left( \frac{1\ \text{m}{{\text{i}}^{2}}}{27,878,400\ \text{f}{{\text{t}}^{2}}} \right)=1.491\times 1{{0}^{6}}\ \text{m}{{\text{i}}^{2}}$ The total land area is $3.537\times {{10}^{6}}\ \text{m}{{\text{i}}^{2}}$. Calculate the percentage of land as follows: \begin{align} & P=\left( \frac{{{F}_{\text{A}}}}{{{T}_{\text{A}}}} \right)\left( 100 \right) \\ & =\left( \frac{1.491\times {{10}^{6}}\ \text{m}{{\text{i}}^{2}}}{3.537\times {{10}^{6}}\ \text{m}{{\text{i}}^{2}}} \right)\left( 100 \right) \\ & =42.15 \end{align} The percentage of land is $\underline{\text{42}\text{.15}}$.