Some Notes on exponential growth:

1) how to calculate an exponential doubling time ( Derivation here )

2) how to determine exponential growth from the data themselves: Its pretty simple. Take the natural log of the ratio of the final population to the initial population and divide that by the number of years between the initial and final populations.

Example:

• Population in 1980 = 23.7 million
• Population in 1993 (14 years later) = 31.2 million
• ratio of final to initial population is 31.2/23.7 = 1.32
• Natural Log of 1.32 (ln 1.32) = 0.28
• 0.28/14 = 0.02 (2% annual growth rate)

http://homework.uoregon.edu/pub/class/hc441/eet.html

Week 7