Chapter Notes
FREQUENCY TABLE A grouping of qualitative data into mutually exclusive classes showing the number of observations in each class.
You can convert class frequencies to relative class frequencies to show the fraction of the total number of observations in each class.
BAR CHART A graph in which the classes are reported on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are proportional to the heights of the bars.
The most common device to present a qualitative variable in graphic form is a bar chart. In
PIE CHART A chart that shows the proportion or percent that each class represents of the total number of frequencies.
A histogram for a frequency distribution based on quantitative data is very similar to the bar chart showing the distribution of qualitative data.
HISTOGRAM A graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are represented by the heights of the bars and the bars are drawn adjacent to each other.
FREQUENCY DISTRIBUTION A grouping of data into mutually exclusive classes showing the number of observations in each class.
Class midpoint and class interval. The midpoint is halfway between the lower limits of two consecutive classes. It is computed by adding the lower limits of consecutive classes and dividing the result by 2.
A frequency polygon also shows the shape of a distribution and is similar to a histogram. It consists of line segments connecting the points formed by the intersections of the class midpoints and the class frequencies.
Chapter Summary
I. A frequency table is a grouping of qualitative data into mutually exclusive classes showing the number of observations in each class.
II. A relative frequency table shows the fraction of the number of frequencies in each class.
III. A bar chart is a graphic representation of a frequency table.
IV. A pie chart shows the