Standard deviation measures how far numbers in a data set are spread out from an average value. In investing, it is used as a measurement of portfolio volatility.

title 'Specifying Standard Process Mean and Standard Deviation'; symbol v=dot c=salmon; proc shewhart history=tape; xrchart weight*sample / mu0 = 1260 sigma0 = 15 xsymbol = mu0 cframe = bigb cinfill = ...

The 4.9% mean and 2.46% standard deviation in the example above is not as reliable as the same values produced from 50 calculations rather than five. So for the example above, 68% of the yearly ...

The following data set (WIRE) contains breaking strength measurements recorded in pounds per inch for 25 samples from a metal wire manufacturing process. The subgroup sample sizes vary between 3 and 7 ...

When you have the average production of three machines, it is easy to calculate the average or mean production. You just add up the three means and divide by three. But what if I want the average ...

An example involving zoo keepers and some very dangerous animals demonstrates that even with the same mean, median and mode, samples can differ greatly. How to calculate standard deviation using ...