Chapter 2: Descriptive Statistics: Tabular and Graphical Displays Flashcards
categorical data
labels or names used to identify categories of like items.
quantitative data
numerical values that indicate how much or how many.
data visualization
a term used to describe the use of graphical displays to summarize and present information about a data set.
frequency distribution
a tabular summary of data showing the number (frequency) of observations in each of several nonoverlapping categories or classes.
relative frequency distribution
a tabular summary of data showing the fraction or proportion of observations in each of several nonoverlapping categories or classes.
percent frequency distribution
a tabular summary of data showing the percentage of observations in each of several nonoverlapping classes.
bar chart
a graphical device for depicting categorical data that have been summarized in a frequency, relative frequency, or percent frequency distribution.
pie chart
a 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
a graphical device that summarizes data by the number of dots above each data value on the horizontal axis.
histogram
a 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.
cumulative frequency distribution
a tabular summary of quantitative data showing the number of data values that are less that or equal to the upper class limit of each class.
cumulative relative frequency distribution
a 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 distribtuion
a 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-lead display
a graphical display used to show simultaneously the rank order and shape of a distribution of data.
crosstabulation
a 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 crosstabulations that can be reversed when the data are aggregated into a single crosstabulation.
scatter diagram
a 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.