To calculate the average deviation from the mean of the dataset {7, 9, 10, 11, 11}, follow these steps:
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Calculate the mean: \[ \text{Mean} = \frac{\text{Sum of data}}{\text{Number of data points}} = \frac{7 + 9 + 10 + 11 + 11}{5} = \frac{48}{5} = 9.6 \]
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Calculate the absolute deviations from the mean:
- For 7: \(|7 - 9.6| = 2.6\)
- For 9: \(|9 - 9.6| = 0.6\)
- For 10: \(|10 - 9.6| = 0.4\)
- For 11: \(|11 - 9.6| = 1.4\)
- For 11: \(|11 - 9.6| = 1.4\)
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Sum the absolute deviations: \[ 2.6 + 0.6 + 0.4 + 1.4 + 1.4 = 6.4 \]
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Calculate the average deviation: \[ \text{Average Deviation} = \frac{\text{Sum of absolute deviations}}{\text{Number of data points}} = \frac{6.4}{5} = 1.28 \]
Therefore, the average deviation from the mean is 1.28.
The correct answer from the provided options is: The average deviation from the mean is 1.28.