The normal distribution describes a symmetrical plot of data around its mean value, where the width of the curve is defined by the standard deviation. It is visually depicted as the "bell curve." ...

would be considered long-tail data points that consequently lie squarely outside of the three-standard-deviation range. Bell Curve vs. Non-Normal Distributions The normal probability distribution ...

which is a normal distribution with the average at 0 and standard deviation as 1, is shown below. The term ‘bell curve’ comes from the shape of the curve, which is a bit like a bell. We will soon make ...