There are several ways to create a histogram using Excel.

The FIRST way:
1. Do all the grouping and counting by hand
2. Enter these categories and counts into Excel
3. Create a bar graph on this processed data (only dealing with a column of bins and a column of frequencies, not the original column of data)
4. Reduce "gap width" on the bars so they touch

The SECOND way to create a histogram with Excel is to use the "Analysis ToolPak" (installation instructions are below) and then let Excel determine the bins (steps a-d in the directions below). Here you are only dealing with the raw data, the single column of data you started with.

The THIRD way to create a histogram with Excel is to use the "Analysis ToolPak" as above, but to specify the bins you wish to use (steps e-f in the directions linked below). Here you are dealing with the raw data, the single column of data, but you've specified bin endpoints in another column.

Here are some ways to enhance a histogram.