About how many people are in the bottom 80% ?

Question

The report Wealth, Income, and Power, claims that the poorest 80% of Americans controlled only 5% of the nation's wealth. In 2013, there were about 316 million people in the US. About how many people are in the bottom 80% ?

Answer 1

Hello! I find that the easiest way to approach this question is to use proportions.

80% is equivalent to 80/100.

For example, if we have 50 apples and 80% of the apples are red, we can find the number of red apples by cross multiplying : (100*x and 50 * 80)

X red apples 80

_______________ = ____________ ---> 100x = 4000

50 total apples 100

Then, we can solve for x by dividing by 100:

100x 4000

100x = 4000 ----> _____= ______ ------> x = 40

100 100

Therefore, if 80% of 50 apples are red, we have 40 red apples.

In this scenario, we know the total number of Americans: 316 million. We want to know how many are in the bottom 80%. We can set up the following proportion, where x is the number of Americans in the bottom 80%. Remember to (1) set up the proportion, (2) cross multiply, (3) solve for x.

X Americans 80

_____________ = _____________ ----> 100x = 25,280,000,000

316,000,000 Americans 100 ____ = _____________ ----> x = 252,800,000 Americans

100 100

Another way of thinking through this is to realize that 80% = 80/100 = 0.80.

Since we know that 80% = 0.80, we can multiply 0.80 by our total number (50 apples or 316 million Americans) to get the same result.

50 apples* 0.80 = 40 apples

316 million Americans * 0.80 = 252,800,000 Americans