Chapter 2 : Organizing and Visualizing Variables Notes

          Chapter 2:  Organizing and Visualizing Variables 

Content

2.1 Organizing Categorical Variables 

    The Summary Table 

    The Contingency Table 

2.2 Organizing Numerical Variables 

     The Frequency Distribution 

     Classes and Excel Bins 

     The Relative Frequency Distribution and the               Percentage

     Distribution 

     The Cumulative Distribution 

2.3 Visualizing Categorical Variables 

     The Bar Chart 

     The Pie Chart and the Doughnut Chart 

     The Pareto Chart 

      Visualizing Two Categorical Variables 

2.4 Visualizing Numerical Variables 

     The Stem-and-Leaf Display 

     The Histogram 

     The Percentage Polygon 

     The Cumulative Percentage Polygon (Ogive) 

2.5 Visualizing Two Numerical Variables 

     The Scatter Plot 

     The Time-Series Plot 

   •The Summary Table - A summary table tallies the set of individual values as frequencies or percentages for each category. A summary table helps you see the differences among the categories by displaying the frequency, amount, or percentage of items in a set of categories in a separate column.

• The Contigency table -A contingency table cross-tabulates, or tallies jointly, the data of two or morecategorical variables, allowing you to study patterns that may exist between the variables.Tallies can be shown as a frequency, a percentage of the overall total, a percentage of the row total, or a percentage of the column total, depending on the type of contingency table you use.Each tally appears in its own cell, and there is a cell for each joint response, a unique combination of values for the variables being tallied. In the simplest contingency table, one that contains only two categorical variables, the joint responses appear in a table such that the tallies of one variable are located in the rows and the tallies of the other variable are located in the columns.