## anonymous 4 years ago Please help - Monthly payments on a 30 year basis for a $32,000 loan at 9% amount to monthly payments of$257.48. Prof gave me formula: m= (Rate*Cost)/(1200*(1-(1+((rate/1200)^(-12* years))))) I keep plugging it in but I am NOT getting what he got?!? Can someone explain how this formula works?

1. anonymous

let me type it in with judicious use of parentheses and see what we get hold on

2. anonymous

ok i think the formula has a mistake in it

3. anonymous

where did the 1200 come from?

4. anonymous

My professor gave it to me. I have no idea.....I have tried solving it every which way but I do not get his answer.

5. anonymous

the one i know is $\frac{3200\times \frac{.09}{12}}{1-(1+\frac{.09}{12})^{-360}}$

6. anonymous

make sure to use -360 and not -12 *30 because that is liable to mess you up in the calculator

7. anonymous

ok (i guess maybe it was a really bad typo?) Thank you so much!

8. anonymous

here is what i got, it matches up as you can see http://www.wolframalpha.com/input/?i=32000%28.09%2F12%29%2F%281-%281%2B%28.09%2F12%29%29^%28-360%29%29%29

9. anonymous

Yeah! Ok, I'll shoot him an email to let him know and continue forward this way. Thanks again!!!!!!

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