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cm | 158 | 159 | 160 | 161 | 162 | 163 | 164 | 165 | 166 |
Total | 1 | 4 | 6 | 6 | 5 | 4 | 7 | 4 | 1 |
ACTIVITY 2
To extract more information from data
[LO 5.3]
Median | 162 cm |
Mode | 164 cm |
Mean | 162 cm |
As you see from the heights of the learners in the previous example, the two classes have different heights but the three averages are exactly the same.
We can tell a little more about the data by using measures of dispersion. These tell us more about how the values are distributed.
158 | 159 | 159 | 159 | 159 | 160 | 160 | 160 | 160 | 160 | 160 | 161 | 161 | 161 | 161 | 161 | 161 | 162 | 162 |
4 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
162 | 162 | 162 | 163 | 163 | 163 | 163 | 164 | 164 | 164 | 164 | 164 | 164 | 164 | 165 | 165 | 165 | 165 | 166 |
0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 |
Measures of dispersion are very useful when you want to compare two sets of data, like the heights of learners in two different classes. There are other measures of dispersion, but they are not taught in this course.
ACTIVITY 3
To use new skills to investigate and compare some test marks
[LO 5.3]
Group A | 82 | 78 | 57 | 91 | 29 | 80 | 85 | 49 | 82 | 67 | 99 | 68 | 83 | 12 | 87 | 86 | 38 | 81 | 58 | 79 |
Group B | 72 | 82 | 74 | 84 | 81 | 84 | 76 | 12 | 2 | 71 | 70 | 93 | 13 | 90 | 80 | 73 | 91 | 70 | 99 | 88 |
ACTIVITY 4
To represent data in ways that make it easier to understand their meaning
[LO 2.2, 2.6, 5.4]
In the work on graphs you saw that a graph gives a much better picture of the meaning of data.
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