Statistics

Characterization of statistical data

• Mod is the value that appears most often in a set of data values.
• The median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. If the data set has an even number of observations, there is no distinct middle value and the median is usually defined to be the arithmetic mean of the two middle values.
• The range of a set of data is the difference between the largest and smallest values. 

Sample average:

$$\overline{x}=\frac{x_1+x_2+x_3+....+x_n}{n}$$

Standard deviation

$$\sigma =\sqrt{\frac{{\left(x_1-\overline{x}\right)}^2+{\left(x_2-\overline{x}\right)}^2+ \cdots +{\left(x_n-\overline{x}\right)}^2}{n}}$$