[Statistics Basic] 2. Descriptive Statistics

 

Descriptive Statistics

Organizing and analyzing the data so that the characteristics of the collected data can be easily grasped, making it easy to interpret.

 

   - Plotting or charting given data

   - Various statistical methods to describe data characteristics such as sum, central tendency(mean),

     degree of spread(variance), median, and correlation coefficient

 

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Frequency distribution table

   - Frequency Distribution Table: Data organization method to understand the shape, center position,

     and distribution of the population's approximate distribution

     (consist of rank, frequency, relative frequency, cumulative frequency)

 

   - Class: Dividing the entire range of data into several subgroups (categories, segments)

   - Frequency: The number of materials belonging to each class

   - Relative Frequency: The ratio of the frequency divided by the total number of data, that is,

     the total frequency (propotion or probability)

     If all relative frequencies are summed, it becomes 1

 

 

Information to gain or lose in frequency distribution table

   - information to get: characteristics of data distribution (concentration, symmetry, etc.)

   - lost information: the numerical value of the data itself

 

 

Graphing frequency distribution table

   - Histogram

   - Graph of Broken Line

   - Bar chart

   - Cumulative percentage curve