• Create a graph that displays key information from quantitative data
• Explain the differences between different graphs that display the same quantitative data

Histograms

histogram

A histogram is a graphical representation using bars where data is grouped into number ranges, called bins, and the frequency of data within each range is the height of the bar. Histograms are a good choice for displaying data sets that have a large number of observations.

Note: Histograms are drawn so that there are no gaps between the bars.

binwidth

The binwidth is the difference in the end points of each bar in a histogram. Binwidths must be equal within a single histogram. The width of the bins can be adjusted so that a histogram will not be overwhelmed by a large number of observations in a data set.

Bins contain the number on their left edge (lowest value), but not the number on their right edge (highest value).

Use the tool and create a histogram for the distribution of age of the Best Actress or Actor winners using the following inputs:

STEP 1: Under “Enter Data,” make sure it says “From Textbook” then under “Dataset” select “Oscars: Age.”
STEP 2: Under “Choose Type of Plot”, select “Histogram.”
STEP 3: Choose “Binwidth” of “1.”

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Changes in the binwidth of a histogram can change the appearance of the distribution. It’s important that a histogram has an appropriate binwidth so that it can give you good information about the shape of the distribution.

The ideal number of bins can range anywhere from [latex]5[/latex] to [latex]10[/latex], but because every data set is different, there is no exact rule. Larger data sets with larger ranges will likely need more bins to display the distribution.