



Statistics 


Use Microsoft Excel to Create a Cumulative Frequency Graph Whilst spreadsheets are good at creating graphs a little bit of creativity is needed in order to create a cumulative frequency graph. A cumulative frequency graphing function is not normally provided. Just as with the manual method for drawing a cumulative frequency graph, the frequency table needs extending to provide a columns for cumulative frequency and also for the upper limits of each class. Once this has been done the normal xy scatter spreadsheet charting function can then be used. The twelve minute video above shows how to use Microsoft Excel (2000/2003) to create a cumulative frequency graph. It starts by extending the frequency table to provide columns for upper limits and cumulative frequency. An extra row is also added for a false or imaginary starting class with a zero frequency (this will provide the starting point for the S shaped curve). The process of creating the CF graph from the two new columns in the table, using the xy scatter option from the chart wizard, is the next part explained; along with how to adjust the scales to ensure that they fit the data being displayed. Once the CF graph has been created, an explanation of how to use the graph to obtain an estimate of the median, upper and lower quartiles, along with how to calculate the interquartile range is then worked through. 


Email: peter@mathstuff.co.uk 

© Peter Compton 