HistogramsWe are learning to…create and analyze

histograms and identify misleading graphs.

Tuesday, April 18, 2023

Histograms vs. Bar Graphs Many people confuse histograms with a bar graph. A histogram looks very similar to a bar graph. There are two

big differences between a histogram and a bar graph.1. A bar graph compares items in categories while a

histogram displays one category broken down into intervals. For example:

A bar graph would compare…the number of apples, to the number of oranges, to the number of bananas at a grocery store.

A histogram would compare…the number of people who eat 0-4 apples a week, to the number that eat 5-9, to the number who eat 10-14.

Histograms vs. Bar Graphs

2. The bars on a histogram touch. The bars found on a bar graph do not touch. Why do you think that the bars will touch on a

histogram? It will make intervals of data easier to compare.

Frequency Chart

A Frequency Chart is a table that breaks data down into equal intervals and then counts the amount data in each interval.

A Frequency Chart is often used to sort a list of data to make a Histogram.

Make a Frequency Chart to display the data below:90, 85, 78, 55, 64, 94, 68, 83, 84, 71, 74, 75, 99, 52, 98, 84, 73, 96, 81, 58, 97, 75, 80, 78

Interval 50-59 60-69 70-79 80-89 90-99

Frequency of Data 3 2 7 6 6

Creating a HistogramInterval 50-59 60-69 70-79 80-89 90-99

Frequency of Data 3 2 7 6 6

Test Scores

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Math Test Scores

50-59 60-69 70-79 80-89 90-99 100-109

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Don’t forget little things…like

labels and equal intervals!

Misleading Histograms

What does it the word “misleading” mean? Deceptive or intentionally create a false impression. Misleading Histograms.xls

Types of Misleading Histograms Combing Intervals: The amount of data in each interval can

make a histograms look different. Stretched Graphs: Graphs might be stretched vertically so

that data looks larger. Excluded Intervals: Intervals may be skipped on the x or y-

axis to make the data look smaller.