Frequency table is one of the commonly used methods to summarize both qualitative and quantitative data. It provides frequencies and relative frequencies for data by class. Frequency table usually consists of the following three columns: 1) Class – one of the categories into which data can be classified; 2) Class frequency – the number of observations in the data set falling into a particular class; 3) Relative frequency – the class frequency divided by the total number of observations in the data set, usually expressed as a percentage. You can create an interactive frequency table in Excel with the PivotTable tool where you can interactively change the variable by which the data is summarized.