Measure of Dispersion

Measure of Dispersion

Read the notes given before answer the questions

Dispersion

• Measures of Dispersion give an idea of how the values of a set of data are scattered

• Dispersion illustrates the extend to which the values in a data are distributed

• Dispersion of a data distribution can be determined by considering the difference between the largest value and the smallest value. If the difference of the value is large, then this shows that the data set is widely dispersed and vice versa.

• If data set has a small range, then the dispersion is small

• Measures of dispersion of set of a data quantitative measures such as range, interquartile range, variance and standard deviation.

Ungrouped data

An ungrouped data set can be represented in various appropriate data representations such as a frequency table, a dot plot and a stem-and-leaf plot that you have been learned to ease the interpretation of data obtained.

Example

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Determine the height of the tallest pupil

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Determine the height of the shortest pupil

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Determine the difference in height between the tallest pupil and the shortest pupil

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State the value of p

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State the value of q

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Determine the longest time taken

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Determine the shortest time taken

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Determine the difference between the longest time and shortest time taken.

Multiple Choice

State the value of p

• 20

• 48

• 23

• 65

Multiple Choice

State the value of q

• 20

• 48

• 23

• 65

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Based on the dot plot, which data shows a wider dispersion?

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Based on the dot plot, which ferry has more consistent number of passangers?