Histograms

NOT Instagrams

Histograms are all about groups of numerical data.

Histograms show intervals of data.

For example, a histogram may show how many people at a Justin Bieber concert were in their teens, twenties, thirties, forties, and fifties.

Histograms, what are they?

20,000

15,000

10,000

5,000

Teens 20’s 30’s 40’s 50’s

Justin Bieber Concert

Example The boys in Mr. Robinson’s Math class earned the following scores on their last exam: 71, 82, 89, 63, 81, 92, 64, 85, 72, 87.

Create a histogram that accurately displays this data.

First, we need to see if there is any we can put our data into groups, or categories. We should put our data into groups of _____________________________________

Let’s Make a Histogram

Make a table that shows how many test scores were in each group.

Let’s Make a Histogram

Test Score Intervals Amount of Tests

60 – 69

70 – 79

80 – 89

90 - 99

71, 82, 89, 63, 81, 92, 64, 85, 72, 87.

Next, we will make a graph from our table. Begin by drawing two intersecting lines:

Let’s Make a Histogram

Use the left side of your paper to set the range from 1 to 5 to match the range from your table.

Then label the bottom of your graph with the test score intervals.

Let’s Make a Histogram

What is the number of persons below the age of 60 in the histogram below?

Solve this question:

If 70 and above is considered a passing grade, how many students passed the math test?

One More Question:

Now, see if you can create a histogram of your data.