HISTOGRAMS

 

A Histogram is a useful graphing tool when you want to analyze groups of data, based on the frequency at given intervals.  The graphing technique allows you to group the data into ‘bins’ so that it can be easily plotted.

            Often, a computer will not have a histogram option in Excel’s Chart Wizard.  A simple 1- time set up is possible so that Histogram analysis of data will be possible.

 

SETTING UP THE PROGRAM

1.  Open an Excel spreadsheet

2.  Go to TOOLS in the menu bar

3.  Select ADD INS

4.      From the drop down bar pick ANALYSIS TOOL PAK (check this box) and click OK

 

MAKING A HISTOGRAM

            On your excel spreadsheet, that contains your data, you will need to make a column for the number of bins that you will need.  The ‘bin’ is the grouping of data based on the range of data you have.  The range of data is often best seen when you use the sorting option from the tool bar:

1.  Go to Data in the menu bar

2.  Select Sort

3.      Choose the column you want to sort and then choose ascending/descending

order.  This allows you to see the range of values and helps you determine the number of bins that you will need.  (The number of bins should cover the range of your data values)

4.  Pick a new column on your spreadsheet and add the bins

5.  Go to TOOLS, DATA ANALYSIS and choose Histogram

6.  For INPUT RANGE, click on the small box to the right.  Highlight the column on your

      spreadsheet that contains the data to be binned.  This will become the frequency value

7.  For the BIN RANGE highlight the bins column

8.  Under OUTPUT OPTIONS, select NEW WORKSHEET PLY: and name the worksheet.

      This will be set up with a new, titled spreadsheet with 2 columns: bin and frequency

9.      Highlight the frequency column of data and go to CHART WIZARD, pick column graph

10. To  be sure your x- axis is labeled as BIN, click on SERIES

       tab, CATEGORY (X) LABELS.  Click on the small box and highlight

       your bins column)

11. Complete the column graph as usual