# Mean deviation (1 Viewer)

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#### synergix

1. The problem statement, all variables and given/known data
I am doing a chemistry lab and I am going to be commenting on the precision of my data in my report I figure that calculating the mean deviation is the best way to do that. I had 6 separate trials in this experiment. I have already calculated the mean which is the same as the average. so is the mean deviation the percent difference between each run and the mean?

(run#/mean)x100= mean deviation for run#

#### symbolipoint

Homework Helper
Gold Member
Be careful that you do not fool yourself. If you really want an AVERAGE DEVIATION, then use the AVERAGE of the ABSOLUTE VALUES of the deviations. Or do you, for some reason, really want the AVERAGE DEVIATION ?

The average of the absolute values of the deviations is likely to be larger than the average deviation. You want to actually use the sizes of the deviations, and some deviations may be positive and some negative.

#### synergix

I think i am just goinlg to calculate the percent difference between the mean and the value that had the largest deviation. and state that in my discussion. calculating the average deviation is not at all required but I am just trying to best express my results. there is no known accepted value with which I can compare my results so the only way to indicate how well I conducted the experiment is by the precision.

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