1. ©G Dear 2010 – Not to be sold/Free to use
Displaying Single
Data Sets
Applied Mathematic
(Preliminary General 1)
Range and IQR
with few scores
Stage 6 - Year 11
Press Ctrl-A
©G Dear 2010 – Not to be sold/Free to use

2. Range = Highest Score – Lowest Score
The Range of a set of scores.
Range = Highest Score – Lowest Score
This gives us a good idea of the spread of the scores.
To buy goods for sale outside this range would be a waste of money.
End of
Slide

3. Range = Highest Score – Lowest Score
The Range of a set of scores.
Range = Highest Score – Lowest Score
A shoe retailer records the sizes of women’s shoes sold on a given day.
4, 5, 6, 7, 9, 6, 8, 5, 7, 6, 7.
Range = 9
- 4
= 5
It would be foolish to buy outside this range,
say a size 3 or 10.
End of
Slide

4. Interquartile Range = Q3 – Q1
The IQR of a set of scores.
Interquartile Range = Q3 – Q1
Upper Quartile
Lower Quartile
Arrange in order
Find the IQR of
4, 5, 6, 7, 9, 6, 8, 5, 7, 6, 7.
Find the median
4, 5, 5, 6, 6, 6, 7 ,7, 7, 8, 9.
Find Q3
IQR = 7
- 5
= 2
Find Q1
This is the range that 50% of results are found.
End of
Slide

5. Interquartile Range = Q3 – Q1
The IQR of a set of scores.
Interquartile Range = Q3 – Q1
Find the IQR of
14, 16, 25, 37, 91, 16, 28, 35, 57, 46, 37.
14, 16, 16, 25, 37, 91, 28, 35, 57, 46, 37.
14, 16, 16, 25, 28, 37, 91, 35, 57, 46, 37.
14, 16, 16, 25, 28, 35, 37, 57, 91, 46, 37.
14, 16, 16, 25, 28, 35, 37, 46, 57, 91, 37.
14, 25, 16, 37, 91, 16, 28, 35, 57, 46, 37.
14, 16, 16, 25, 28, 35, 37, 46, 57, 37, 91.
14, 16, 16, 25, 28, 35, 37, 91, 57, 46, 37. X X X X X X X X X X
Arrange in order
Find the median
Find Q1
Find Q3
Median = 35
Q3 = 57
Q1 = 16
IQR = 57 – 35 = 22
Range = 91 – 14 = 77
End of
Slide

6. Interquartile Range = Q3 – Q1
IQR and an even set of scores.
Interquartile Range = Q3 – Q1
Find the IQR of
5, 12, 23, 31, 35, 47, 55, 57, 63, 66, 77, 78, 82, 95.
Median = (55+57)÷2
= 56
Q1 =
= 31
Q3 =
= 77
IQR = 77 – 31
= 46
Range = 95 – 5
= 90
End of
Show