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Excel is a powerful tool for the visual display of data. Leveraging graphs and tables is a useful way to gain a deeper understanding of your data than by just looking at a large data set in its raw form. It is also an effective way to communicate your data to others.
There are a variety of types of graphs (called Charts in Excel) that you can create in Microsoft Excel, including column (or vertical bar) graphs, line graphs, line and point graphs, area graphs, scatter plot graphs, pie graphs, and others.
One special type of graph that you can create in Excel is the histogram, or a vertical bar chart. The histogram is useful for showing count data (quantities of something) across multiple sub-divisions of a category. Displaying counts in a histogram is a form of frequency distribution.
Examples of when to use a histogram include:
a. How many pieces of Halloween candy did each kid in the class collect?
b. How many widgets did each salesperson sell in February?
c. How many days in the month of August did the temperature exceed 100 degrees?
To create Excel histogram charts, follow these steps:
1. Group the data within the category you want to display as a histogram into a table so that there is a unique (summed) quantity per sub-division (a sub-division could be: each kid in the class, each salesperson, each day of the month of August, etc.). For example, if you have a data table that shows that Bob sold 1 widget on February 3 and 2 widgets on February 16, you need to group all of Bob's sales for the month into one line that shows 3 widgets (no need to include the date of the sale, since this information is non-essential for this histogram). You can do this grouping through a combination of sorting and addition, or you can use PivotTables.
2. Your data table should be arranged into two columns: the first column showing each sub-division (again: each kid in the class, each salesperson, etc.) and the other showing the quantity assigned to each sub-division. Make sure each column has a descriptive header in the first row. Note: do not add sub-totals or totals to your table.
3. Sort your table by either the sub-division name or quantity column - your choice.
4. Next, highlight the two columns of data, including the column headers.
5. Click on the Insert tab at the top of your worksheet, then click on the little black down arrow underneath the Column icon in the Charts section.
6. Select the first chart you see, at the top, left of the drop-down menu. Your histogram should then appear on your worksheet.
7. One last step: I suggest adding data labels to your graph to make it easier to read. To do this, just select (click on) any one of the columns in the graph and right click, then select Add Data Labels from the menu.
Histograms are a useful tool for communicating information visually, and with a little practice they are easy to make in Excel.
