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View Full Version : Bell shaped curve in Excel



Mike
25-10-2006, 07:48 AM
How would I create a bell-shaped curve in Excel? I have a pair of columns of data - information about the same thing from two different sources - and I want to plot a bell-shaped curve based on the difference between each record in the two columns. The differences range from about -2 to +2. It's been a while since I had to do anything like this (like when I was studying... and I only learned it for the exam... if you know what I mean ;))

Mike.

pico
25-10-2006, 01:34 PM
Hmmm... Its been a while since I've done any Stats too!! I'm not quite sure of what you are after but if the data is normally distributed it should display a normal distribution when plotted. So you just need to know what to plot.

Depending on how many data points you have to work with, I'd suggest creating small intervals say 0.1 from your lowest data point (around -2) all the way up to your highest (+2). So one interval will be 0 to 0.1, another 0.5 to 0.6. Then count the number of points that fall within each interval and plot them versus the average of the interval (ie for 0.1 to 0.2 use 0.15 for the x axis).

I think thats how it works!!

HTH

Parry
25-10-2006, 09:23 PM
Ask and ye shall receive...

http://support.microsoft.com/kb/213930