Re: What difference does a few percent make?

Author: Theresa Lynn Ford

Created: Thursday, 1/27/2005 9:43 AM

**What difference does a few percent make?**

**We are presently at 6.2 billion people.**

**(1) If the population growth of the world was at 3% each year how many people will there be in 20 years, by the year 2024?**

The formula for exponential growth is: N(t) = N(0) x e |
Where: N() is the quantity t is the time e is the natural logarithm r is the rate N(0) is the starting quantity N(t) is the quantity after the time has passed |

With 6.2 billion in 2004, N(0)=6.2 and the formula is: N(20) = 6.2 x e^{(.03 x 20)}N(20) = 6.2 x e^{(.6)}N(20) = 6.2 x 1.8221188 N(20) = 11.2971366 Therefore the population in 2024 is approximately 11.3 billion.

More Information:

- Other Population Growth Formulas

http://www.arcytech.org/java/population/facts_math.html - Google's Fine Calculator

http://www.google.com/search?num=100&hl=en&lr=&q=6.2*%28e%5E%280.03*20%29%29&btnG=Search