afdmello said:
Now what is this term rolling average
If that is not rhetorical....
Although some people do say "rolling average", the more-common term is
"moving average". If you Google the latter term, you should find lots of
information. Start with a wiki article.
Also note that there are many kinds of "moving averages". When the term
is used without qualification, it usually refers to an arithmetic mean.
(Although some people might compute a moving geometric mean in some
situations, namely a time series.)
A typical method is.... Suppose you have weekly data over a long-ish
period of time, say in A1:A52. You might compute a 4-week or 8-week
moving average putting the following formula into B4 (for 4-week; B8 for
8-week) and copying down:
=AVERAGE(A1:A4)
When you copy down, A1:A4 will change to A2:A5, A3:A6, etc. That is a
"moving" average.
My data is as follows [....]
Month jan feb march apr
Planned 10 14 15 10
caliberated 5 15
Pls forgive my ignorance but this is all new to me
how do I get a rolling average? this data is just
collected from Jan 2010
Don't feel bad. I do not consider myself "ignorant" on the subject, yet
even I do not understand what is expected of you.
First, you say you have data "from Jan 2010". Is that the 2 months shown
on the line labeled "calibrated"?
If so, 2 data points is not sufficient to create a moving average. Even 4
data points ("planned") would not be very useful.
Second, someone needs to tell the length of the period for the moving
average -- how many data points per average.
My suggestion.... First, read a wiki article on "moving average". That
will help you understand the concept. Second, return to those who are
assigning the task and ask for clarification, or at least more data.
My suspicion is: they misused the term "moving average". I suspect they
mistakenly ass-u-me-d that a "moving average" is the solution to whatever
problem they actually want to solve.
Perhaps they are looking for some statistical measure of how well the
actual ("calibrated"?) is tracking the "planned".
----- original message -----
afdmello said:
Gentlemen,
I have been assigned a new task, to make a score card for Key Performance
Indicators. I have asked the concerned departments for the data.
Now what is this term rolling average/
My data is as follows
Data : safety valve caliberation
Month jan feb march apr
Planned 10 14 15 10
caliberated 5 15
Pls forgive my ignorance but this is all new to me how do I get a rolling
average? this data is just collected from Jan 2010
afd