This deep dive covers Applications of 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 9 of 11 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Applications of Cumulative Frequency
Finding Percentiles
To find the value below which p% of the data lies:
- Calculate position: (p/100) × n
- Use the same method as finding median
- Example: 90th percentile position = (90/100) × 43 = 38.7
Finding How Many Below a Value
To find how many data items are below a certain value:
- Draw vertical line from the value to the curve
- Draw horizontal line to y-axis
- Read the cumulative frequency
Comparing Distributions
- Median: Shows typical value
- IQR: Shows spread of middle 50%
- Shape: Steep curve = data clustered, gentle curve = data spread
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.