Connecting the Dots

Overview

Connecting the Dots is about data handling: collecting, organising and representing data, then reading it from tables and graphs to draw conclusions.

Key concepts

• Data is information collected as numbers or facts.
• Organising data using tables and tally marks.
• Representing data with bar graphs and pictographs.
• Finding the mean (average) of data.

Important formulae

• Mean = sum of observations ÷ number of observations
• Range = highest value − lowest value
• Mode = the most frequently occurring value

Solved example

1. Find the mean of 4, 6, 8, 10.
2. Sum = 4 + 6 + 8 + 10 = 28.
3. Mean = 28 ÷ 4 = 7.

Important questions

1. Find the range of 12, 5, 9, 20, 7.
2. What is the mode of 2, 3, 3, 5, 3, 8?
3. Find the mean of 15, 25, 35.
4. Why are bar graphs useful for comparing data?

Quick revision

Organise data in tables, then show it with bar graphs or pictographs. The mean is the total divided by the count, the mode is the most common value, and the range is the spread.