Three Popular Data Displays

KEY TAKEAWAYS

Graphical representations of large data sets provide a quick overview of the nature of the data.
A population or a very large data set may be represented by a smooth curve. This curve is a very fine relative frequency histogram in which the exceedingly narrow vertical bars have been omitted.
When a curve derived from a relative frequency histogram is used to describe a data set, the proportion of data with values between two numbers $a$ and $b$ is the area under the curve between $a$ and $b$ , as illustrated in Figure 2.6 "A Very Fine Relative Frequency Histogram".