Posted by inez on Friday, May 7, 2010 at 12:25am.
A certain country's population P(t), in millions, t years after 1980 can be approximated by P(t) = 2.495(1.019)^t. Find the doubling time.

algebra  Reiny, Friday, May 7, 2010 at 1:06am
solve
4.990 = 2.495(1.09)^t
2 = 1.09^t
log 2 = tlog1.09
t = log2/log1.09 = 8.043 
algebra  inez, Friday, May 7, 2010 at 2:04am
48,6 yr
58.4 yr
36.8 yr
or
73.7 yr 
algebra  Reiny, Friday, May 7, 2010 at 8:12am
I should really have my eyes checked soon, lol
I saw 1.09 instead of 1.019
so last line
t = log2 / log 1.019 = 36.8 years