Of the 6.25 billion people in the world, 310 million live in North America. What percent of the world's population lives in North America?

1 Answer
Nov 30, 2016

#4.1bar3 %#

Explanation:

#"percentage of people in North America" = "number of people in America"/"word population" times 100#

We can use powers of 10 to simplify a lot.

#=(310000000)/(7500000000) times 100#

#=(31times10^7)/(75times10^8) times 10^2#

#=(31times10^7times10^2times10^-8)/75#

#=(31times 10^(7+2-8))/75#

#=(31*10^1)/75#

#=310/75#

Now we can make this number divided by 100 to make a decimal out of it by multiplying both the numerator and the denominator by #4/3#.

#=(310 * 4/3)/(75*4/3)#

#=(1240/3)/(300/3)#

Now we can find some common factors to simplify these numbers.

#=(413 1/3)/((cancel3*100)/cancel3)#

One third is in decimal places .3 and infinitely repeats itself.
#=(413.bar3)/100 = 4.1bar3#

#= 4.1bar3 %#