Learning pack · IGCSE handout

Cumulative Frequency

What's in this pack: printable worksheet PDF, matching answers PDF (IGCSE / Secure–Stretch practice). Cumulative frequency graphs estimate medians and quartiles and lead to box plots and interquartile range.

Resources at the top · full summary · videos with short notes below.

🎒 Resources in this pack

Jump straight to the printable files, or scroll to the summary and videos.

Scaffolded Learning Sheet — attempt the worksheet, then use the Answers for a full written solution.

📝 Open Learning Sheet ✅ Open answers 🎬 More topic videos (2)📖 Full summary

Files: 32_cumulative_frequency_handout.pdf · 32_cumulative_frequency_handout_answers.pdf

Full topic summary

Cumulative frequency graphs estimate medians and quartiles and lead to box plots and interquartile range.

Key learning points

Plot upper-class boundaries against running totals; join with a smooth curve.
Median at total $/2$ ; Q1 at total $/4$ ; Q3 at $3\times$ total $/4$ .
IQR = Q3 − Q1 measures spread of the middle half.

Worked example 1 — Reading the median

CF graph, $n=80$ . CF height for the median?

Working

40

Read across from $n/2$ .

Worked example 2 — IQR

UQ $=12$ , LQ $=5$ . IQR?

Working

7

UQ − LQ.

Worked example 3 — Plotting

CF is plotted against which x-value?

Working

\text{upper class boundary}

Running total to the end of the class.

🎬 Topic videos

Cumulative Frequency Diagrams - GCSE Higher Maths
1st Class Maths · 12 min
Cumulative frequency curves. CIE 0580 / Pearson 4MA1.
Outliers, Box Plots and Cumulative Frequency - Year 1 Statistics [A-level]
1st Class Maths · 23 min
Classroom-ready explain of averages. Use when teaching this topic in Lower Secondary / IGCSE.

More Lower Secondary packs

Browse the hub Learning Packs & Summary, or open the compact Cumulative Frequency summary.