frequency polygon

If random distributions are large enough then their frequency polygons take on a predictable shape known as the normal distribution.

Frequency tables and frequency polygons are also used at more advanced levels of graphing.

D.23 Construct frequency polygons for grouped discrete data.

They use measures of average and range with associated frequency polygons, as appropriate, to compare distributions and make inferences.

A frequency polygon from the histogram above:

A frequency polygon is the shape created by connecting the centres of the tops of the histogram bars with straight lines.

Histographs A histograph, or frequency polygon, is a graph formed by joining the midpoints of histogram column tops.

• What is the percentage difference between the first and the second most common length of service? 2. d) Draw a histogram to represent the data and plot the frequency polygon.

Best used when portraying category values in descending order. histogram Shows discrete or continuous variable data in a similar way to column graphs, but without the gap between the columns. histograph (frequency polygon) Depicts continuous variable data.

Use and interpret diagrams for continuous data, including frequency polygons and stem and leaf diagrams; identify the modal class; compare distributions and make inferences, using the shapes of the distributions and measures of average and range.