Posted by mema on .
Wk 6
Sec 12.7 #24
World population growth
In 2008 the world population was 6.7 billion and the exponential growth rate was 1.14% per year.
A.Find the exponential growth function
B.Predict the world’s population in 2014
C.When will the world’s population be 8.0 billion?
Could someone help me with this please?

Algebra 
MathMate,
Growth function:
Assume Y=year, so Y=2008 is year 2008, etc.
The exponential growth function is
N(Y)=N(2008)*1.0114^(Y2008) for Y≥2008
or
N(Y)=(6.7*10^9)*1.0114(Y2008)
for Y≥2008
Population at 2014 is therefore
N(2014)=(6.7*10^9)*1.0114(20142008)
=7.17*10^9
The population will reach 8 billion when
N(Y)=8*10^9
or
(6.7*10^9)*1.0114(Y2008) = 8*10^9
1.0114(Y2008)=8/6.7
Take log on each side and solve for Y:
Y2008=log(8/6.7)/log(1.0114)=15.6 years
So by the middle of 2023, the world population will reach 8 billions.