Presentation of Quantitative Data

• Bar chart


  A chart with bars whose lengths are proportional to quantities

  
• Histograms


  - Used when data is continuous

  - The bars touch each other

  
• Scattergrams


  - They show associations between co-variables not differences

  - Either of the variables can be placed on the X/Y axis

  
• Normal distribution


  A function that represents the distribution of variables as a symmetrical bell-shaped graph.

  
• Skewed distributions


  - When the spread of data is not symmetrical meaning the data clusters to one end.

  - The mode is located at the highest point, then the median and finally the mean.

  
• Positive skew

  
• Negative skew