Histograms, Frequency Polygons, and Ogives
histogram
a graph that displays data by using contiguous vertical bars of various heights to represent the frequencies of the classes
frequency polygon
a graph that displays the data by using lines that connect points plotted for the frequencies at the midpoints of the classes. The frequencies are represented by the heights of the points.
ogive
a graph that represents the cumulative frequencies for the classes in a frequency distribution
cumulative frequency
the sum of the frequencies accumulated up to the upper boundary of a class in the distribution
relative frequency graphs
used when the proportion of data values that fall into a given class is more important than the actual number of values that fall into that class