Answer
99.4 years
Work Step by Step
21900000 is current population
43800000 is anticipated population
0.7% growth per year
$43800000=21900000*(1.007)^x$
$43800000/21900000=21900000*(1.007)^x/21900000$
$2= 1.007^x$
$log 2 = log {1.007^x}$
$log 2 = x log {1.007}$
$log 2/log 1.007 = x log 1.007/log 1.007$
$log 2/log 1.007 =x$
$.30103/.00303 =x$
$99.349 =x$
