2. Histograms Presented by William 2 ! (William Chen and Gulian)

3. What it is  A histogram looks like a bar graph but instead divides the data set into different ranges. Over each range is placed a block or rectangle whose height represents the number of data values in the range.  A frequency histogram uses vertical columns to show frequencies (without using ranges) such as :  How many times a score occurs

4. When to use TTo group numbers in a data set into ranges WWeight HHeight AAge TTime SShow frequencies (without using ranges)

5. Data needed  One numerical data set  Ranges to group the data set in (unless creating a frequency histogram)  Title  Axes Labels

6. Real Life Example  How long is your bus ride to/from school?  Your answers (in min.):

7. How we did it Prerequisites (for both): 1.Collect data. 2.Decide ranges to group data in.* Computer: 3.Enter data in Microsoft Excel. 4.Select data and insert Column/Bar Graph. 5.Select the bars on the chart, right-click, then select “Format Data Series”. 6.Slide the “Gap Width” slider all the way to “No Gap”. 7.Customize so it is creative/original! Handwritten: 3.Draw x- and y- axes and label the x-axis as your ranges/numbers and your y-axis as frequencies. 4.Draw your bars like in a bar graph but with no gaps in between. (This is a difference between a bar graph and histogram.) 5.Decorate! *Skip step if you are creating a frequency histogram. (If you are making a frequency histogram, don’t use ranges.)

8. Checking for Understanding WWhat percentage of the class has bus rides longer than 20 minutes? AAbout 43%

9. Advantages vs. Disadvantages  Numbers are grouped into ranges so that trends can be observed  Can show frequencies  Actual data (numbers) not actually seen  Can only graph one data set

10. Thank you! http://www.mathsisfun.com/data/histograms.html http://www.google.com/imghp?hl=en&tab=wi The combined brainpower of William 2 !