1. Histograms

2. Vocabulary Qualitative data Quantitative data
data collected that involve words
Quantitative data
data collected that involve numbers

3. Definition of a Histogram
A Histogram displays a range of values of a variable that have been broken into groups or intervals.
1. To make a Histogram, you divide the range of data into intervals of equal length
2. Frequency Table: Count the number of observations in each interval
3. Represent each interval with a bar indicating the number in that interval

4. Disenfranchisement Rates for all 50 States
8.1
24.9
6.6
9.2
1.5
17.1
3.9 14
11.3
2.8
1.2
4.6
16.1
3.1 3
10.3 5
17.4
7.2 4
2.4
7.9
24.7
14.2
8.3
14.3 16
18.9
5.7
0.8
0.7
3.5
12.9
6.2
4.2
2.6
3.7
8.4

5. Disenfranchisement Rates for all 50 States
Percents 30 25 20 15 10 5

6. Step 1: Sort the Data from Lowest to Highest
2.6 4
7.9 14
2.8
8.1
14.2
0.7
4.2
8.3
14.3
0.8 16
1.2
4.6
8.4
16.1
1.5 3 5
9.2
17.1
3.1
5.7
17.4
3.5
6.2
10.3
18.9
2.4
3.7
6.6
11.3
24.7
3.9
7.2
12.9
24.9

7. Step 2: Determine how many groups of data you want to have.
For example, we’ll use 5 groups
Step 3: Determine the approximate range of the set of data
0% through 24.9% (approximately 25%)
Step 4: From Steps 2 and 3, determine the range of each individual group
I decided to have 5 groups. The range is from 0% - 25%. 25% divided by 5 is 5%. So each group should have a range of 5%.

8. Step 5: Make a Frequency Table
Interval
Frequency
0% - 5% 25
5%-10% 12
10% - 15% 6
15% - 20% 5
20% - 25% 2

9. Disenfranchisement Rates for all 50 States
Step 6: graph each group
Disenfranchisement Rates for all 50 States
Percents 30 25 20 15 10 5