Cumulative frequency diagram example | Find Median, Quartiles & IQR | IGCSE Maths

In this video, I solve an example on Cumulative Frequency Diagrams step by step. This lesson will help you understand how to interpret the graph and use it to calculate important statistical measures such as:
✅ Median – the middle value of the data
✅ Lower Quartile (Q1) – the value below which 25% of data lies
✅ Upper Quartile (Q3) – the value below which 75% of data lies
✅ Interquartile Range (IQR) – a measure of data spread, calculated as Q3 – Q1
Caution ⚠️ It is not necessary that on x axis of cumulative frequency graph, always time is there.

You will also learn how to read values accurately from the cumulative frequency curve and apply them to real exam-style questions.

📌 What you’ll learn in this video:

How to plot and interpret a cumulative frequency diagram

How to find the median, Q1, and Q3 directly from the graph

How to calculate the interquartile range (IQR)

Why quartiles and IQR are important in data analysis

Common exam mistakes to avoid when working with cumulative frequency

This tutorial is especially useful for IGCSE Maths (Cambridge, Edexcel, and O Level) students preparing for exams. By the end of the video, you’ll be confident in tackling cumulative frequency problems in your past papers and scoring full marks.

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#IGCSE #Maths #CumulativeFrequency #Statistics #Quartiles #Median #IQR

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Source: Example taken from Savemyexams— solution by Maths by Zahfran