Statistics

• Describes the characteristics of a set or population of numbers

• There are many metrics used in statistics, including mean, median, & mode. Advanced metrics include standard deviation (meaning spread or variation) or range (max – min)

Histogram / PDF / Frequency Plot

• A histogram (or probability density function) shows the mean and the standard deviation for a given set of data.

• Mean defines the average of the data (see mean below)

• Standard deviation (σ) defines the spread of the data (see -3 sd, -2 sd, etc below)

• A normal distribution shows the typical distribution of data for a survey