Question

Suppose $9,400 is invested in an account at an annual interest rate of 3.2% compounded
continuously. How long (to the nearest tenth of a year) will it take the investment to double in
size?

Answer 1

\[9400(1.032)^t=18800\]
\[(1.032)^t=2\]
\[t*\log{1.032}=\log{2}\]
\[t=log{2}/log{1.032}\]
t is about 22. (Little bigger than 22)

Answer 2

Answer: 22 years.