I'm sure this is simple and uses the present value formula somehow, but I don't know the exact formula!!
For an investment to grow fourfold in 9 years, at what annual rate must the investment grow?
Hello, DooBeeDoo!
You just need the Compound Interest Formula . . .
For an investment to grow fourfold in 9 years,
at what annual rate must the investment grow?
Assuming that investment is compounded annually,
. . the formula is: .
. . where: .
In this problem, we have: .
We have: .
Take the 9th root: .
. . Therefore: .