Mean— A mathematical average of a group of numbers

Average Deviation = (Sum of all Deviations)/(# of Measurements) i.e., dav =(di/n where, n is a number of data % Relative Average Deviation = dav/xav x 100. Standard Deviation = [(Sum of all deviations squared/ (# of measurements – 1)]1/2 . dst = s = [ (((xav - xi(2/(n-1))]1/2 = [((di2/(n-1))]1/2. Variance is a square of a standard deviation: ................
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