Level 4: Choosing and showing

Statistics and data · level 4 of 8 · rough age 11-12 (a guide for parents; anyone can start anywhere)

In level 3 you learned to find the mean, the median, the mode and the range, and to draw stem-and-leaf plots and line graphs. In this level you learn to choose: which average gives a fair picture, which graph suits which data, and how to tell when a graph is fooling you. You also meet the tools people use for real data: histograms for many measurements, circle graphs for parts of a whole, infographics, and the spreadsheet, which does the arithmetic for you.

Lesson	You will be able to
Which average is fair?	Explain how an outlier drags the mean, and choose the mean, median or mode to fit the data and the question
Histograms	Group data into equal intervals, draw a histogram, choose an interval width, and tell a histogram from a bar graph
Circle graphs	Turn counts into percents and angles, draw and read a circle graph, and say when one fits
Infographics	Read an infographic that mixes charts, numbers and pictures, and judge whether it is clear and honest
Spreadsheets for data	Enter and sort data, compute the mean, median, mode and range with formulas, and make a chart
Graphs that mislead	Spot cut-off axes, uneven intervals, 3D pies and pictures scaled the wrong way, and redraw them honestly

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