ABSTRACT
The first step in telling data stories is summarising the available data. Descriptive statistics are tools that use a single number to describe a distribution. Analysts calculate averages, medians, percentiles and other statistical summaries to represent a data set's tendency, spread, positions and shape. Statisticians have defined five types of descriptive statistics: frequency, central tendency, position, dispersion and shape. This chapter shows how to calculate descriptive statistics using synthetic water quality data from an imaginary city. The learning objectives for this chapter are:
Summarise water quality data using various descriptive statistics
Evaluate compliance of water quality data with relevant regulations.
Perform grouped data analysis
