Question 1140177

{{{ F = Pe^(rt) }}}
 <br>
r = annual interest rate (as a decimal value)
t = number of years
P = present value
F = future value
<br>
The problem can be solved without using $1450, as it is the same doubling time
for any starting principal (the P's cancel):<br>
{{{ 2P = Pe^(0.075t) }}}<br>
{{{  ln(2) = 0.075t }}}<br>   
{{{  t = ln(2)/0.075 }}} or about <b>9.24</b> years (approx 9 years 3 months)