Histograms

Definition of a Histogram A Histogram displays a range of values of a variable that have been broken into groups or intervals. Histograms are useful if you are trying to graph a large set of quantitative data To make a Histogram, you divide the range of data into intervals of equal length, count the number of observations in each interval, and represent each interval with a bar indicating the number of observations.

Disenfranchisement Rates for all 50 States

Step 1: Sort the Data from Lowest to Highest

Step 2: Determine how many groups of data you want to have. Step 3: Determine the approximate range of the set of data Step 4: From Steps 2 and 3, determine the range of each individual group For example, we’ll use 5 groups 0% through 24.9% (approximately 25%) 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%.

Step 5: Make a list of the groups you will be using. Step 6: Using your data, count how many numbers fall into each group Group 1: 0% - 5% Group 2: 5% - 10% Group 3: 10% - 15% Group 4: 15% - 20% Group 5: 20% - 25% Group 1: 0% % Group 2: 5% % Group 3: 10% % Group 4: 15% % Group 5: 20% - 25%

Step 7: graph each group