IQR = Q3 - Q1: Challenge & Extension

Mathematics
Year 9
12 questions
~24 mins
1 views0 downloads

About This Worksheet

A worksheet exploring the calculation and application of the Interquartile Range (IQR = Q3 - Q1) with increasing difficulty and real-world contexts.

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IQR = Q3 - Q1: Challenge & Extension

Subject: MathematicsGrade: Year 9
Name:
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Untitled Worksheet

Grade Year 9
A

Practice Questions

Answer all questions. Show your working in the grid spaces provided.
1.
Calculate the first quartile (Q1) and third quartile (Q3) for the dataset: 12, 15, 14, 10, 18, 20, 16, 13.
[3 marks]
2.
Using your previous answer, find the interquartile range (IQR).
[2 marks]
3.
Construct a box plot on the grid to represent the dataset: 21, 24, 19, 22, 26, 20, 23, 25. Indicate Q1, Q3, and the median.
[4 marks]
4.
A class's test scores (out of 100) are: 55, 67, 70, 72, 79, 85, 90, 92, 95. Calculate Q1, Q3, and the IQR.
[3 marks]
5.
In a dataset, Q1 = 15 and Q3 = 35. What is the IQR?
[1 mark]
6.
A survey of daily hours spent on homework shows Q1 = 2 hours and Q3 = 5 hours. If the IQR is 3 hours, what is the median?
[2 marks]
7.
A student calculates the IQR of a data set as 10. If Q1 = 25, what is Q3?
[1 mark]
8.
A box plot shows Q1 = 12, median = 15, and Q3 = 18. What is the IQR?
[1 mark]
9.
Identify and correct the mistake in this calculation: Q1 = 10, Q3 = 25, IQR = 20.
[3 marks]
10.
A dataset has Q1 = 8 and Q3 = 22. The data is skewed to the right. Explain briefly how IQR helps understand data spread in this context.
[3 marks]
11.
Calculate the IQR if Q1 = 14 and Q3 = 29.
[2 marks]
12.
A data set's median is 50, Q1 is 40, and Q3 is 60. What is the interquartile range?
[2 marks]

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Details

Created
1/1/2026
Updated
1/1/2026
Type
worksheet