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MA33-04 Maths Coming soon

Reading estimates from a cumulative frequency diagram

MA33-04

This lesson is coming soon.

In this lesson

Estimate the median, quartiles and interquartile range from a cumulative frequency curve, and explain what a cumulative frequency value represents.

What it covers

  • Interpreting what a point on a cumulative frequency curve represents, including inequality notation
  • Finding the median by reading across from n/2 on the cumulative frequency axis
  • Finding the lower quartile (n/4) and upper quartile (3n/4) from the curve
  • Calculating the interquartile range as upper quartile minus lower quartile
  • Estimating a percentile, or the number of data values above/below a given value, using the curve

Key words

For: AQA GCSE 8300, Edexcel GCSE 1MA1, Edexcel IGCSE 4MA1, Eduqas GCSE C300, OCR GCSE J560, Cambridge IGCSE 0580

On the specification

BoardSpecStatement
AQA GCSE 8300S3Construct and interpret diagrams for grouped discrete data and continuous data, ie histograms with equal and unequal class intervals and cumulative frequency graphs, and know their appropriate use
Edexcel GCSE 1MA1S3Construct and interpret diagrams for grouped discrete data and continuous data, i.e. histograms with equal and unequal class intervals and cumulative frequency graphs, and know their appropriate use
Edexcel IGCSE 4MA1H6.1BConstruct cumulative frequency diagrams from tabulated data
Edexcel IGCSE 4MA1H6.1CUse cumulative frequency diagrams
Edexcel IGCSE 4MA1H6.2AEstimate the median from a cumulative frequency diagram
Eduqas GCSE C300HS4Construct and interpret diagrams for grouped discrete data and continuous data, i.e. histograms with equal and unequal class intervals and cumulative frequency graphs, and know their appropriate use
OCR GCSE J56012.02bInterpret and construct diagrams for grouped data as appropriate, i.e. cumulative frequency graphs and histograms (with either equal or unequal class intervals).
OCR GCSE J56012.03aCalculate the mean, mode, median and range for ungrouped data. Find the modal class, and calculate estimates of the range, mean and median for grouped data, and understand why they are estimates. Describe a population using statistics. Make simple comparisons. Compare data sets using `like for like' summary values. Understand the advantages and disadvantages of summary values.
Cambridge IGCSE 0580E9.6Draw and interpret cumulative frequency tables and diagrams.
For teachers

This GCSE Maths lesson teaches reading estimates from a cumulative frequency diagram. By the end, students should be able to estimate the median, quartiles and interquartile range from a cumulative frequency curve, and explain what a cumulative frequency value represents. It works through two worked examples and the mistakes examiners report.