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.

Answer 1

solve
4.990 = 2.495(1.09)^t
2 = 1.09^t
log 2 = tlog1.09
t = log2/log1.09 = 8.043

Answer 2

48,6 yr

58.4 yr

36.8 yr

or

73.7 yr

Answer 3

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