# Math Help - Present value of $1 per week 1. ## Present value of$1 per week

Hi folks,

I've been desparately trying to work out the underlying formula for the attached table. If someone could assist me in this, I would be grateful.

Thanks

2. Originally Posted by Scuzzie
Hi folks,

I've been desparately trying to work out the underlying formula for the attached table. If someone could assist me in this, I would be grateful.

Thanks
My first thought would be to graph it and see what it looks like. Have you done this yet?

-Dan

3. Hi Dan, no I haven't graphed it because what I need is the underlying equasion for the attached table and then I can adapt it to calc different multiples of weeks and parts thereof.

4. Present value of \$1 a week from now is .9989 which means there is an interest rate of .11% per week. An annuity is the present value of a series of payments.

The resulting equation is a series depending on how many weeks you want to sum:

$\sum_{k=1}^{n+1} \frac{1}{1.0011^k}$