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Glossary

Statistics & Probability – Key Terms & Definitions

Essential statistics & probability vocabulary for IGCSE Mathematics (0580). Each term includes a clear definition and example to help you understand and remember key concepts.

mean

Core

Sum of values divided by count

Example

3+5+73=5\dfrac{3+5+7}{3} = 5

median

Core

Middle value when ordered

Example

In 2,5,8 median is 5

mode

Core

Most frequent value

Example

In 3,3,5,7 mode is 3

range

Core

Difference between highest and lowest

Example

Range of 2,5,9 is 7

frequency

Core

How many times a value occurs

Example

Score 5 appeared 8 times

cumulative frequency

Core

Running total of frequencies

Example

Add each frequency to previous total

probability

Core

Chance of event happening, 0 to 1

Example

P(heads) = 0.5

sample space

Core

All possible outcomes

Example

Dice: {1,2,3,4,5,6}

tree diagram

Core

Diagram showing sequential probabilities

Example

Multiply along branches

histogram

Extended

Bar chart where area represents frequency

Example

Height = frequency density

frequency density

Extended

Frequency divided by class width

Example

Used in histograms

pie chart

Core

Circle divided into sectors by proportion

Example

360° represents total

interquartile range

Core

Q3 minus Q1

Example

Middle 50% spread

quartile

Core

Values dividing data into quarters

Example

Q1, Q2 (median), Q3

correlation

Core

Relationship between two variables

Example

Positive, negative, or none

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Frequently Asked Questions

How many statistics & probability terms do I need to know for IGCSE?

This glossary covers 15 key statistics & probability terms. Focus on understanding definitions and being able to use each term in context during exams.

Are these terms for Core or Extended?

Terms are labelled as Core or Extended. Core students should focus on Core-labelled terms, while Extended students need to know all terms.

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