Frequency Histogram and Polygons

A frequency histogram is a column graph for numerical data in which the columns touch. In NSW Year 8 maths (NESA outcome MA4‑DAT‑C‑01) a frequency polygon is drawn over it by joining the middle of each column top and closing the line down to the axis at both ends.

You will read histograms of single values and of grouped data, find class centres, the modal class, the total and a percentage, and calculate a mean from a histogram. You will also spot a mistake in a histogram’s scale, compare two polygons on the same axes, combine two classes’ histograms and rebuild a histogram from clues. Data includes flathead lengths, parkrun times and screen time. It is part of Year 8 Investigating Data.