Averages and spread

Averages and spread for GCSE Psychology AQA Higher: what it means, how to set the working out, and the questions it is asked in.
  • GCSE
  • AQA
  • Psychology
  • Higher
  • Spec S10
  • 6 min read
  • 6 revision boxes

Introduction

2 boxes
4 min read

What is averages and spread?

Listen to this box

Transcript

A short spoken summary of averages and spread and where it is used.

A spoken walk-through of averages and spread before you read the notes.
Read the units in the question before you start; a converted unit is the most common slip.
The layout below is the one the mark scheme expects.

Diagram showing averages and spread laid out step by step

The same idea drawn out, so the method is visible.
Worth knowing: x2+5x+6=0x^2 + 5x + 6 = 0.
6 rows

The averages and spread reference table

The specification wording is precise here, and the mark scheme follows that wording exactly.
Term
Meaning
Example
Common slip
Row 1 column 1
Row 1 column 2
×10\times 10 moves every digit one column left
Row 1 column 4
Row 2 column 1
Row 2 column 2
×10\times 10 moves every digit one column left
Row 2 column 4

Learning

2 boxes
5 steps

How to work with averages and spread

Work through the method one line at a time and write down what changes at each step.
The layout below is the one the mark scheme expects.

Diagram showing averages and spread laid out step by step

The same idea drawn out, so the method is visible.
Worth knowing: ×10\times 10 moves every digit one column left.
  1. Read the question and write down what is being asked for.
  2. Set out the working for averages and spread in the order the method gives.
  3. Substitute the values and simplify.
Start from the definition and substitute the numbers the question gives you.
Simplify one line at a time: x2+5x+6=0x^2 + 5x + 6 = 0.
Answer: 49=7\sqrt{49} = 7
2 rules

Key facts: Averages and spread

Check the answer against an estimate before you move on, so a place-value slip is caught here.
  • Rule 1

    How averages and spread behaves in the 1st of the cases the specification names.
    49=7\sqrt{49} = 7
  • Rule 2

    How averages and spread behaves in the 2nd of the cases the specification names.
    34×25\frac{3}{4} \times \frac{2}{5}
  • Rule 3

    How averages and spread behaves in the 3rd of the cases the specification names.
    34×25\frac{3}{4} \times \frac{2}{5}

20 minutes

Get your predicted grade

Twenty questions gives you a predicted grade, your target, and the gap between them — plus the topics that close it fastest.

Examples

2 boxes
2 marks · worked

Worked example: averages and spread

Work through the method one line at a time and write down what changes at each step.
3 marks · worked

Practice question 6: a2+b2=c2a^2 + b^2 = c^2

This idea appears again in the higher-mark questions, so it is worth over-learning.
The layout below is the one the mark scheme expects.

Diagram showing averages and spread laid out step by step

The same idea drawn out, so the method is visible.
Worth knowing: ×10\times 10 moves every digit one column left.

Practice bank

Thousands of revision questions

Every topic is backed by graded practice with instant marking and full solutions.
Try it now
Practice questions
3,000+
Topics
10
Marking and solutions
Instant

Common questions

How many marks is averages and spread usually worth?
Between one and four, depending on how many steps the question asks for.
Is this on the GCSE Psychology AQA Higher paper?
Yes — it sits in the Data and information strand.