Last one for the night and my homework is done. Woohoo. :)

When P dollars is invested at interest rate i, compounded annually, for t years, the investment grows to A dollars, where A=P(1 + i)^t. Find the interest rate if $2490 grows to $3630 in 2 years. Round your answer to the nearest hundredth of a percent.

Question

Last one for the night and my homework is done. Woohoo. :)

When P dollars is invested at interest rate i, compounded annually, for t years, the investment grows to A dollars, where A=P(1 + i)^t. Find the interest rate if $2490 grows to $3630 in 2 years. Round your answer to the nearest hundredth of a percent.

anonymous · Answer

3630/2490 = x^2 +2x+1

anonymous · Answer

go from there

anonymous · Answer

$$2490(1+i)^2=3630$$
$$(1+i)^2=\frac{3630}{2490}=1.4578$$

anonymous · Answer

$$1+i=\sqrt{1.4578}$$
$$i=\sqrt{1.4578}-1$$

anonymous · Answer

$$i=.2074$$ or 20.74% i would love to get that!

anonymous · Answer

hope this helped you get through the assignment.

anonymous · Answer

you are really good. thanks man.

anonymous · Answer

welcome.  oh one more thing. if you are going to solve 
$$(x+1)^2=somthing$$ don't multiply out. just take $$x+1=\pm\sqrt{something}$$

anonymous · Answer

we didn't need the minus here because we wanted a positive answer

anonymous · Answer

ok. will remember. my head hurts. haha. thanks

anonymous · Answer

welcome