# Calculating Error

by simpleton
Tags: error
 P: 59 Hi all, I am trying to use excel to do error analysis. I have a set of data points, and I have the average value and standard deviation of all the data points (which I use to plot the error bars). I want to use the excel to plot the best fit line and extreme line to get the error. However, it seems that excel does not allow me to draw extreme lines :( Therefore, I was wondering if there is a way for me to calculate out the error, if I am given the standard deviation of all the datapoints and the equation of the best-fit line. The value I want is the gradient of the graph with its associated error. Does anyone know how to draw extreme lines in excel? If not, can someone tell me how I can calculate the error of the gradient? Thanks!
 P: 51 You have error bars so I'm guessing you know the error for each point. You can make a seperate column on excel, add or subtract the error from each point (new point = old point + 0.05... for example), and then add this data set to the graph. That should be your error curve.
 P: 59 Hi mrmiller1, Thanks for your reply. However, it seems that when I set error bars, the error bars for all the points will be the same. Is there a way for you to set different error bars for different points? Also, do you know a way to physically draw in the error curve or extreme line? Thanks in advance! On a sidenote, I am using excel 2007.

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