# Summation Problem

• Dec 29th 2010, 12:22 AM
me123
Summation Problem
Hi,

Can anyone please help me on how to solve for p in terms of n and k in the following equation?

Attachment 20278

Thank you.

Regards
• Dec 29th 2010, 09:35 AM
Moo
Hello,

Why do you need this ? Is it a probability based question ? Is it the real wording of the question ?

Because as far as I can see, there are multiple solutions (Surprised)
• Dec 29th 2010, 03:23 PM
me123
Hi,

It is not exactly a probability question. This is part of my research where I need to find the intersection of the 2 curves for 0<p<1 given a fixed n and k. I am not majoring in mathematics and hence am having problems with solving it.

Attachment 20284

I don't think that there are multiple solutions as you have pointed out. In particular, (1) is monotonically increasing while (2) is a lateral reflection of it which is monotonically decreasing. So there must a a unique p that solves it.

By the way, I suspect that p=(k-1)/(n-1) from a series of graphs I have plotted but just can seem to prove it analytically.