Hello-

Was hoping for some insight into a solution for a specific issue...

I'm trying to estimate the earned value of a set of assets, where the known variables are the starting and ending values, and time.

At first, I thought the formula for continuously compounding interest (solving for interest rate) would be the ticket:

r = ln(A/P)^1/t

where:

A= final value,

P = starting value

t = time

r = interest rate

But then I realized that I am not dealing with a closed system-- i.e., the starting value is being incremented continuously during time period t... for example:

Start with 100 units; end with 1,000 units. Each unit creates interest. However, over time period t (say one year), 2 units were added to A every day. What was the interest earned on all the units deposited?

So I suppose I'm looking for some sort of series to describe this activity?

Forgive me if I'm not making sense... I figure there's a formula for this that would make life easy..

Thank you all in advance.