Descriptive statistics

Descriptive statistics

1. By : Juan Pablo Hernandez Gutierrez

2. Central tendency

   • There are three main measures of central tendency: the mode, the median and the mean. Each of these measures describes a different indication of the typical or central value in the distribution.
     • Median
     • Mode
     • Mean

3. Normal distribution

   • Z score
   • Uses
   • Shapes & properties
   • Normal distribution, also known as the Gaussian distribution, is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean

4. Dispersion

   • Statistical dispersion means the extent to which numerical data is likely to vary about an average value.
     • Range
     • Standard deviation
     • variation around a central value

5. Distribution

   • normal distribution, chi square distribution, binomial distribution, and Poisson distribution.
   • A statistical distribution, or probability distribution, describes how values are distributed for a field. In other words, the statistical distribution shows which values are common and uncommon.

6. Variable types

   • Variables may be classified into two main categories: categorical and numeric. Each category is then classified in two subcategories: nominal or ordinal for categorical variables, discrete or continuous for numeric variables
     • Categorical variables
     • Quantitative variables
       • Outliers
       • Shape of the distribution
       • Measures of center
       • Measures of spread