This deep dive covers Finding the Median from Cumulative Frequency within Cumulative Frequency for GCSE Mathematics. Revise Cumulative Frequency in Statistics for GCSE Mathematics with 14 exam-style questions and 20 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 6 of 11 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Finding the Median from Cumulative Frequency
Method
- Find the median position: n ÷ 2 (where n = total frequency)
- Draw horizontal line: From the median position on y-axis to the curve
- Draw vertical line: From where the horizontal line meets the curve down to x-axis
- Read the median: Value where the vertical line meets the x-axis
Example
Total frequency (n) = 43
Median position = 43 ÷ 2 = 21.5
Draw horizontal line from 21.5 on y-axis to curve, then vertical line to x-axis.
Median ≈ 175 cm
Median position = 43 ÷ 2 = 21.5
Draw horizontal line from 21.5 on y-axis to curve, then vertical line to x-axis.
Median ≈ 175 cm
Practice questions for Cumulative Frequency
Cumulative frequency is:
The graph shows the times for 60 students. The cumulative frequency at 40 seconds reads as 48. Estimate the number of students who took longer than 40 seconds to complete the puzzle.
Quick recall flashcards
How do you calculate cumulative frequency?
Start with the first frequency. For each subsequent class, add the current frequency to the previous cumulative frequency:
CF₂ = CF₁ + f₂
CF₃ = CF₂ + f₃, and so on.
What is cumulative frequency?
Cumulative frequency is the running total of frequencies up to and including each class. It shows how many data values fall below the upper boundary of each class.