1986 AMC 12 第 8 题

Question

美国在

1980

年的人口为

226{,}504{,}825

。国土面积为

3{,}615{,}122

平方英里。每平方英里有

(5280)^2

平方英尺。下列哪个数最接近人均占有的平方英尺数？

The population of the United States in

1980

was

226{,}504{,}825.

The area of the country is

3{,}615{,}122

square miles. There are

(5280)^2

square feet in one square mile. Which number below best approximates the average number of square feet per person?

5{,}000

10{,}000

50{,}000

100{,}000

500{,}000

用总平方英尺数除以人口

Divide total square feet by population

相乘前，将已知数四舍五入到两位有效数字

Round the given values to two significant digits before multiplying

平均值约为

\begin{aligned} &\frac{(3.615\times10^6)(5280)^2} {2.265\times10^8}\\ &\qquad\approx 4.45\times10^5 \end{aligned}

平方英尺/人。在各选项中，它最接近

500{,}000

。

所以正确答案是 E。

The average is approximately

\begin{aligned} &\frac{(3.615\times10^6)(5280)^2} {2.265\times10^8}\\ &\qquad\approx 4.45\times10^5 \end{aligned}

square feet per person. Of the choices, this is closest to

500{,}000.

Thus the correct answer is E.

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