Distribution of a Quantitative Variable

The standard graphing choices expand considerably when we have quantitative data—particularly for continuous variables or discrete variables with many possible values. For one thing, it's not at all obvious where we would "slice the pie" or just where to set boundaries between the bars in a bar chart.

As such, most graphing tools for quantitative data establish arbitrary boundaries, which we can adjust appropriately to the context of the data. As a way of visualizing the distribution of a continuous variable, the most commonly used graph is a histogram. A histogram is basically a bar chart with values of the variable on one axis and frequency on the other. Let's illustrate.

In our data set, we have estimated ...

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