Summary/Background
You must be clear about how to find the median, upper quartile (UQ) and lower quartile (LQ) from a cumulative frequency graph. To find the median you should start from the point halfway up to the total frequency on the vertical axis, draw a line across to the curve and then down to the horizontal axis. To find the LQ and UQ you start from a quarter and from three-quarters the way up on the vertical axis.Remember that the Interquartile range = Upper quartile - Lower quartile.
You should know how to draw a number of other statistical diagrams too, including:scatter diagrams, pie charts, bar charts, line graphs, stem & leaf diagrams and box & whisker plots
Software/Applets used on this page
Glossary
axis
One of two straight lines on a graph from which measurements are taken. One axis (the y axis) is vertical; the other (the x axis) is horizontal.
frequency
Of a function: the rate of repetition of a periodic function.
In statistics: the number of occurances of a value
In statistics: the number of occurances of a value
graph
A diagram showing a relationship between two variables.
The diagram shows a vertical y axis and a horizontal x axis.
The diagram shows a vertical y axis and a horizontal x axis.
interquartile range
A measure of dispersion; the difference between the upper and lower quartiles; Q3-Q1.
median
the middle value of a set of data that has been arranged in order of magnitude; half the data values are above it and half are below.
quartile
In an ordered set of data 25% are below the first (Q1), 50% are below the second (Q2), 75% are below the third (Q3).
range
In Statistics: the difference between the largest and smallest values in a data set; a simple measure of spread or variation
In Pure Maths: the values that y can take given an equation y=f(x) and a domain for x.
In Pure Maths: the values that y can take given an equation y=f(x) and a domain for x.
union
The union of two sets A and B is the set containing all the elements of A and B.
This question appears in the following syllabi:
| Syllabus | Module | Section | Topic | Exam Year |
|---|---|---|---|---|
| AQA AS Maths 2017 | Statistics | Data Presentation and Interpretation | Cumulative Frequency | - |
| AQA AS/A2 Maths 2017 | Statistics | Data Presentation and Interpretation | Cumulative Frequency | - |
| AQA GCSE (9-1) Higher (UK) | S: Statistics | S3: Grouped Data, Histograms and Cumulative Frequency | Cumulative Frequency | - |
| CBSE X (India) | Statistics and Probability | Statistics | Cumulative frequency graph | - |
| CIE IGCSE (9-1) Maths (0626 UK) | 9 Statistics | E9.7 Cumulative Frequency and Box-Plots | Cumulative Frequency | - |
| Edexcel AS Maths 2017 | Statistics | Data Presentation and Interpretation | Cumulative Frequency | - |
| Edexcel AS/A2 Maths 2017 | Statistics | Data Presentation and Interpretation | Cumulative Frequency | - |
| Edexcel GCSE (9-1) Higher (UK) | S: Statistics | S3: Grouped Data, Histograms and Cumulative Frequency | Cumulative Frequency | - |
| GCSE Higher (UK) | Statistics | Displaying data | Cumulative frequency | - |
| OCR AS Maths 2017 | Statistics | Working with Data | Cumulative Frequency | - |
| OCR GCSE (9-1) Higher (UK) | 12: Statistics | 12.02b: Grouped Data | Cumulative Frequency | - |
| OCR MEI AS Maths 2017 | Statistics | Working with Data | Cumulative Frequency | - |
| Universal (all site questions) | D | Displaying data | Cumulative frequency | - |