Grade 5 · Unit 9: Data representation and interpretation

Interpreting data

Averages and misleading graphs.

Cricket statistics

Cricket commentators love averages. Mean, median and mode summarise data. Each tells a different story.

Three averages

Mean: add all, divide by how many. Median: put in order, take the middle. Mode: the most common.

Which average?

One very large value pulls the mean up. The median is more typical here. Choose the average that best describes the data.

Misleading graphs

Check where the axis starts. Check the scale is even. Graphs can be misleading – read them critically.

Working backwards

If 4 scores have a mean of 15, the total must be 60. Many sets of data fit: 15, 15, 15, 15 or 10, 14, 16, 20. Make a hypothesis, collect data, test it and refine your idea.

What I learnt

• I can find the mean, median, mode and range.
• I can choose a suitable average.
• I can spot misleading graphs.