The lower quartile, median and upper quartile are usually denoted by Q_1, Q_2 and Q_3. To find them you must first arrange the data in order of size.
If n is odd, then Q_2 is the \frac{1}{2}(n+1)th value. If n is even the median is halfway between the \frac{1}{2}nth value and the next.
To find Q_1 find the median of the lower half of the data. To find Q_3, find the median of the upper half of the data.
If n is odd, then Q_2 is the \frac{1}{2}(n+1)th value. If n is even the median is halfway between the \frac{1}{2}nth value and the next.
To find Q_1 find the median of the lower half of the data. To find Q_3, find the median of the upper half of the data.
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This question appears in the following syllabi:
Syllabus | Module | Section | Topic | Exam Year |
---|---|---|---|---|
AQA A-Level (UK - Pre-2017) | S1 | Summarising data | Measures of location | - |
AQA AS Maths 2017 | Statistics | Data Presentation and Interpretation | Measures of Central Tendency | - |
AQA AS/A2 Maths 2017 | Statistics | Data Presentation and Interpretation | Measures of Central Tendency | - |
CBSE XI (India) | Statistics and Probability | Statistics | Range, mean deviation, variance and standard deviation of grouped data | - |
CCEA A-Level (NI) | S1 | Summarising data | Measures of location | - |
CIE A-Level (UK) | S1 | Summarising data | Measures of location | - |
Edexcel A-Level (UK - Pre-2017) | S1 | Summarising data | Measures of location | - |
Edexcel AS Maths 2017 | Statistics | Measures of Data | Measures of Central Tendency | - |
Edexcel AS/A2 Maths 2017 | Statistics | Measures of Data | Measures of Central Tendency | - |
I.B. Standard Level | 5 | Summarising data | Measures of location | - |
Methods (UK) | M14 | Summarising data | Measures of location | - |
I.B. (MSSL) | 6 | Summarising data | Measures of location | - |
OCR A-Level (UK - Pre-2017) | S1 | Summarising data | Measures of location | - |
OCR AS Maths 2017 | Statistics | Central Tendency and Variation | Measures of Central Tendency | - |
OCR MEI AS Maths 2017 | Statistics | Central Tendency and Variation | Measures of Central Tendency | - |
OCR-MEI A-Level (UK - Pre-2017) | S1 | Summarising data | Measures of location | - |
Pre-U A-Level (UK) | Prob | Summarising data | Measures of location | - |
Scottish (Highers + Advanced) | HS | Summarising data | Measures of location | - |
Scottish Highers | S | Summarising data | Measures of location | - |
Universal (all site questions) | S | Summarising data | Measures of location | - |
WJEC A-Level (Wales) | S1 | Summarising data | Measures of location | - |