1. Bar Graphs vs. Histograms
Day 4 Unit 8
Bar Graphs vs. Histograms
PRINCESS C. BARCEGA
APG SCHOOL, MANAMA, BAHRAIN

2. What do you know about
bar graph?
double bar graph?
Histogram?

3. Bar Graph A bar graph can be used to display and compare data
The scale should include all the data values and be easily divided into equal intervals.
Have you had a lot of experience with a bar graph?

4. How to interpret a Bar Graph?
The bar graph shows Mr. Snowden’s students by gender and band membership.
How many of Mr. Snowden’s students are band members?
How many of Mr. Snowden’s students are not band members?

5. Double Bar Graph Can be used to compare two related sets of data
Have you seen this type of graph before?

6. Double Bar Graph
You will see double bar graphs a lot in reporting the weather on the news like the one to the left.

7. Histogram
Histogram is a bar graph that shows the frequency of data within equal intervals.
Frequency means how many or how much.
There is no space in between the bars.

8. NO GAPS between Bars
Continuous data

9. Bars are different in width
Determined by Grouped Frequency Distribution

10. Since you have made bar graphs so much in lower math classes and you can probably infer how to make a double bar graph from the one I showed you…
Let’s look at how to construct a histogram.

11. Creating Histograms Middle School Math
Aligned to Common Core State Standards

12. Histograms Histograms are used to organize and interpret data.
Histograms are often used with frequency tables to give a more visual view of the data.
Each bar represents an interval that contains data.
The height of the bar indicates the frequency of the data.
Interval
Tally
Frequency
0-1
2-3
4-5
6-7
6-7

13. Create a frequency table.
A professional football team scored the following number of points in games last season. Create a frequency table that reflects this information.
17, 24, 13, 16, 34, 38, 27, 13, 24, 13, 7, 0, 13, 10, 14, 0, 26, 23, 31, 7
First decide what intervals to use in your frequency table. Finding the minimum and the maximum really help to decide intervals. Intervals must be the same width!
Intervals
Tally Marks
Frequency

14. Create a frequency table.
A professional football team scored the following number of points in games last season. Create a frequency table that reflects this information.
17, 24, 13, 16, 34, 38, 27, 13, 24, 13, 7, 0, 13, 10, 14, 0, 26, 23, 31, 7
First decide what intervals to use in your frequency table.
Scores
Tally Marks
Frequency
0 – 9
 4
10 – 19
  8
20 – 29 5
30 – 39
 3

15. Build the histogram.
Use the frequency table to help build the histogram.
17, 24, 13, 16, 34, 38, 27, 13, 24, 13, 7, 0, 13, 10, 14, 0, 26, 23, 31, 7
Scores
Tally Marks
Frequency
0 9
 4
10 19
  8
20  29 5
30  39
 3

16. Build the histogram.
Use the frequency table to help build the histogram.
17, 24, 13, 16, 34, 38, 27, 13, 24, 13, 7, 0, 13, 10, 14, 0, 26, 23, 31, 7
Scores
Tally Marks
Frequency
0 9
 4
10 19
  8
20  29 5
30  39
 3