Final answer:
The best approximation of the United States population in 2014 is option a. 3 · 10⁸ people, as it is closest to the reported figure and correctly uses three significant figures.
Step-by-step explanation:
When approximating the population of the United States in 2014, it is important to consider significant figures and the context of the estimation. The population reported in January 2014 was approximately 317,297,725, and when we account for uncertainties in measurement, it is more practical to express this with three significant figures as 3.17 x 108 people.
Given the two options provided:
- a. 3 · 108 people
- b. 3 · 109 people
The best approximation of the United States population in 2014 is a. 3 · 108 people. This represents three hundred million (300,000,000) people, which is closest to the actual reported figure.
It is worth noting that population figures include a level of estimation due to factors such as births, deaths, and migration. When significant figures are considered, the population should be expressed in a way that does not overstate the precision of the data, which is why three significant figures are appropriate.