Chapter 2: Descriptive Statisitcs - Tabular and Graphical Displays

Frequency Distribution

Tabular summary of data showing the number (frequency) of observations in each of several non-overlapping categories or classes.

Relative Frequency

Relative Frequency Distribution

Tabular summary of data showing the fraction or proportion of observations in each of several non-overlapping categories or classes.

Percent Frequency Distribution

Tabular summary of data showing the percentage of observations in each of several non-overlapping classes

Bar Chart

Graphical display for depicting categorical data summarized in a frequency, relative frequency, or precent frequency distribution.

Pie Chart

Graphical Device for presenting data summaries based on subdivision of a circle into sectors that correspond to the relative frequency for each class.

Class Midpoint

The value halfway between the lower and upper class limits.

Dot Plot

Graphical device that summarizes data by the number of dots above each data value on the horizontal axis.

Histogram

Graphical display of a frequency distribution, relative frequency distribution, or percent frequency distribution of quantitative data constructed by placing the class intervals on the horizontal axis and the frequencies, relative frequencies, or percent frequencies on the vertical axis.

Class Width

Cumulative Frequency Distribution

Tabular summary of quantitative data showing the number of data values that are less than or equal to the upper class limit of each class.

Cumulative Relative Frequency Distribution

Tabular summary of quantitative data showing the fraction or proportion of data values that are less than or equal to the upper class limit of each class

Cumulative Percent Frequency Distribution

Tabular summary of quantitative data showing the percentage of data values that are less than or equal to the upper class limit of each class.

Stem-and-Leaf Display

Graphical display used to show simultaneously the rank order and shape of a distribution of data.

Cross-tabulation

Tabular summary of data for two variables. The classes for one variable are represented by the rows; the classes for the other variable are represented by the columns

Simpson’s Paradox

Conclusions drawn from two or more separate cross-tabulations that can be reversed when the data are aggregated into a single cross-tabulation.

Scatter Diagram

Graphical display of the relationship between two quantitative variables. One variable is shown on the horizontal axis and the other variable is shown on the vertical axis.

Trendline

A line that provides an approximation of the relationship between two variables/

Side-by-Side Bar Chart

A graphical display for depicting multiple bar charts on the same display.

Stacked Bar Chart

A bar chart in which each bar is broken into rectangular segments of a different color showing the relative frequency of each class in a manner similar to a pie chart.

Data Dashboard

A set of visual displays that organizes and presents information that is used to monitor the performance of a company or organization in a manner that is easy to read, understand, and interpret.