If an investment of $2500 grows to $4406.43 in nine years with interest compounded annually, what is the interest rate? (Round your answer to one decimal place.)

I got up to (1+i)^9=1.762572
and now I don't know what to do next.

Question

If an investment of $2500 grows to $4406.43 in nine years with interest compounded annually, what is the interest rate? (Round your answer to one decimal place.) 

I got up to (1+i)^9=1.762572 
and now I don't know what to do next.

campbell_st · Answer

so you have to yake the 9th root of 1.762572


use $$1.782572^{x}$$

where x is the power that represents the 9th root

anonymous · Answer

Okay, I got 155.984

campbell_st · Answer

nope there is an error there... of the power is 9... how do you write the opposite so that you have the 9th root..$$\sqrt[9]{1.762572}$$

anonymous · Answer

1.762572 to the 9th root would then be 1.065000108

anonymous · Answer

Argh...okay right I got that part

campbell_st · Answer

ok.. so you have 

1.065 = 1 + r/100

solve for r...

anonymous · Answer

Got it! 6.5% ...thank you once again!

campbell_st · Answer

good luck with your maths

anonymous · Answer

i also have a compound interest question but its a little more difficult >.<