Maths / Basic Statistics(1)
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Answer
Frequency
Frequency Histogram - Book review
Assignment
8
7
6
5
4
3
2
1
0
12 |
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Assignment Mark
Boxplots
Boxplots are a pictorial display which shows the spread of a dataset.
X |
X |
Lower |
Lower |
Median |
Upper |
Upper |
Extreme |
Quartile |
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Quartile |
Extreme |
The following results are from a university exam:
Lower extreme: |
22 |
Lower quartile: |
31 |
Median: |
57 |
Upper quartile: |
69 |
Upper extreme: |
95 |
X |
X |
Practise Questions: |
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Draw the boxplots for the following data sets |
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a) |
1 |
2 |
3 |
5 |
5 |
6 |
7 |
9 |
b) |
7 |
8 |
10 |
11 |
11 |
12 |
14 |
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Answers |
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First, split the data set in two: |
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a) |
1 |
2 |
3 |
5 |
5 |
6 |
7 |
9 |
LQ |
= |
2+3 / 2 |
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UQ |
= |
6+7 / 2 |
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= |
2.5 |
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= |
6.5 |
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Lower extreme: |
1 |
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Lower quartile: |
2.5 |
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Median: |
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5 |
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Upper quartile: |
6.5 |
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Upper extreme: |
9 |
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X
X
b) |
7 |
8 |
10 |
11 |
11 |
12 |
14 |
Median = 11 (don’t include in LQ and UQ calculation)
Split dataset in two: |
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7 |
8 |
10 |
11 |
12 |
14 |
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LQ =8 |
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UQ = 12 |
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Lower extreme: |
7 |
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Lower quartile: |
8 |
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Median: |
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11 |
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Upper quartile: |
12 |
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Upper extreme: |
14 |
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X |
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