# Thread: Find the initial investment?

1. ## Find the initial investment?

Captinblack invested some money at 10% compounded quarterly at the end of three years his investmenthad grown to $2488.05. Find the initial investment. My answer is$1850.00 thanks for checking.

2. Greetings Kwtolley:

I have but one word to utter in response to your work here today...Perfect!

Enjoy,

Rich B.

3. Hello, kwtolley!

Captain Blackbeard invested some money at 10% compounded quarterly.
At the end of three years his investmenthad grown to $2488.05. Find the initial investment. My answer is$1850.00

I assume you used a variation of : .$\displaystyle A\;=\;P\left(1 + \frac{i}{n}\right)^{nt}$

Then: .$\displaystyle P \;=\;\frac{2488.05}{\left(1 + \frac{0.10}{4}\right)^{12}} \;=\;1850.00422 \;\approx\;\$1850$~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ It's hard to see your work from here . . . It looks like you played the$\displaystyle J\heartsuit$instead of the$\displaystyle 7\clubsuit$. Then you transposed to the key of$\displaystyle F\sharp\text{ minor}$instead of$\displaystyle E\flat\text{ major}\$.

Lucky for you, the two errors canceled out.