Calculating average rate of change in real time

[Geoff Halsall]

I have a real time numerical value in cell A1.
5 seconds later this value updates into cell A2,
then in another 5 seconds it updates into cell A3.
This continues in this way up to say cell 200

How can I calculate the average rate of change
with respect to all the numerical values in column A
at any given time

Would really appreciate any help

Thanks

 

[bbott]

bbott, for percentage change, why not the simpler =(A2-A1)/A1, which is equivalent to =(A2/A1)-1. Or if you're concerned about cells moving around, =(A2/OFFSET(A2,-1,0))-1

It depends if you just want to see the current % change or retain all of the changes. Using (A2-A1)/A1, you would need to copy the formula down. If it's a real-time update every 5 seconds with an undetermined number of changes, that wouldn't be very efficient. My approach uses a single cell that updates with each change to show the current % change. User preference, I guess .