“With Earth’s Population Now at 7 Billion, How Many People Have Ever Lived,” Nancy Szokan, Washington Post, October 31, 2011. http://www.washingtonpost.com/national/health-science/with-earths-population-now-at-7-billion-how-many-people-have-ever-lived/2011/10/27/gIQA6SLtZM_story.html

has been cited by the following article:

• TITLE: Modeling Population Growth: Exponential and Hyperbolic Modeling

  AUTHORS: Dean Hathout

  KEYWORDS: Exponential Growth Modeling; Hyperbolic Growth Modeling

  JOURNAL NAME: Applied Mathematics, Vol.4 No.2, February 27, 2013

  ABSTRACT: A standard part of the calculus curriculum is learning exponential growth models. This paper, designed to serve as a teaching aid, extends the standard modeling by showing that simple exponential models, relying on two points to fit parameters do not do a good job in modeling population data of the distant past. Moreover, they provide a constant doubling time. Therefore, the student is introduced to hyperbolic modeling, and it is demonstrated that with only two population data points, an amazing amount of information can be obtained, such as reasonably accurate doubling times that are a function of t, as well as accurate estimates of such entertaining topics as the total number of people that have ever lived on earth.