MA32-03 Maths Coming soon
Estimating the mean from grouped data
MA32-03
This lesson is coming soon.
In this lesson
Estimate the mean from a grouped frequency table using true class midpoints, dividing by the total frequency, and explain why the result is only an estimate.
What it covers
- Find the true midpoint of each class (average of lower and upper class boundaries)
- Sum (midpoint x frequency) across all classes
- Divide that sum by the TOTAL frequency, not the number of classes
- Explain why the result is only an estimate (individual values within a group aren't actually known)
Key words
For: Cambridge IGCSE 0580, Edexcel IGCSE 4MA1, OCR GCSE J560
On the specification
| Board | Spec | Statement |
|---|---|---|
| Cambridge IGCSE 0580 | E9.3 | Calculate the mean, median, mode, quartiles, range and interquartile range for individual data and distinguish between the purposes for which these are used. |
| Edexcel IGCSE 4MA1 | F6.2C | Calculate an estimate for the mean for grouped data |
| OCR GCSE J560 | 12.03a | Calculate 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. |
For teachers
This GCSE Maths lesson teaches estimating the mean from grouped data. By the end, students should be able to estimate the mean from a grouped frequency table using true class midpoints, dividing by the total frequency, and explain why the result is only an estimate. It works through two worked examples and the mistakes examiners report.