Frequency, Percentage, and Proportion

Statistical Based Graphical Displays

Frequency Polygon• a graph that displays the data using lines to connect

points plotted for the frequencies. • The frequencies represent the heights of the vertical

bars in the histograms.

• Ex: Frequency Polygon superimposed on the weight class histogram.

Frequency Polygon

Stem-and-Leaf Plots• AKA Stem-and-Leaf Displays • part of the data value is used as the stem – forms from the data classes

• the remaining part of the data is used as the leaves – forms form the actual data values

Consider the following numerical data96, 98, 107, 110, 112

Ex: Consider the following numerical data96, 98, 107, 110, 112

Stem-and-Leaf Plots

Ex: Consider the following numerical data96, 98, 107, 110, 112

Stem-and-Leaf Plots

Stem and Leaf

Time-Series Plots• AKA Time-Series Graph • displays data that are observed over a given period of

time• typically represented as a line segment

Time-series plot

Pie Chart• AKA Pie Graph • displays data in a circle that is divided into slices

according to the percentage of the data values in each category (qualitative data) or class (quantitative data).

Category: Blood Type

Frequency f

A 5

B 8

O 8

AB 4

Total 25

Pie Chart