9514 1404 393
Answer:
about 6.93%
Explanation:
The multiplier for compound interest at annual rate r is ...
e^(rt)
We want that multiplier to be 2 when t=10. Solving for r, we get ...
2 = e^(10r)
ln(2) = 10r . . . . . take the natural log
r = ln(2)/10 ≈ 6.93%
You need a continuous interest rate of about 6.93% for an investment to double in 10 years.