Some Statistical Terms used in Six Sigma

Mean: Average (more specifically called the arithmetic mean), the sum of a series of values divided by the number of values.

Median: Midpoint in a series of values.

Mode: Value that occurs most often in a series of values.

Range: Difference between the highest value and the lowest value in a series, the spread between the maximum and the minimum.

Standard Deviation: Average difference between any value in a series of values and the mean of all the values in that series. This statistic is a measure of the variation in a distribution of values.