Histogram

I'm having trouble matching your solution to the practical example problems to what I have as a histogram. I have rewatched the videos and read over the downloadable notes and nothing has directed me into knowing how to set up a histogram the way you guys have. When I go to adjust the x axis, the only options available for me to edit it is "Options > Gap Width". Also, once I select the entire data and select histogram, all I get is two bar charts both under a two large groups of prices. Instead of being separated by the my desired interval width of 5. Thanks in advance! Hector