What does standard deviation of a set of data tell you?

Standard Deviation tells you how many measurements for a group are spread out from the average (mean), or expected value Or in simple means how many standard deviations are withing the mean

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.

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