What is an outlier in math and can you get rid of it?

Answer 1

An outlier, in a distribution of data points, is a value which does not fall within three standard deviations of the mean. You cannot, at least directly, remove an outlier without biasing the data itself, but you can choose different measures to try and soften their effects. For example, instead of using mean as a measurement for the central value of the data set, one can use median.