Introduction

In many real-life situations, it is helpful to describe data by a single number that is most representative of the entire collection of numbers. Three ways of characterizing any data distribution are:

• Measures of Central Tendency.
  Describe the center point of a data set with a single value.
  
  
• Measures of Dispersion.
  Describe how far individual data values have strayed from the mean.
  
  
• Measures of Skewness and Kurtosis.
  Describe the degree of asymmetry and peakedness of a distribution, usually taken relative to a normal distribution.