To compare the variability of the datasets using standard deviation, let's calculate the standard deviation for both datasets.
Dataset A: 11, 7, 12, 8, 9, 5
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Mean: \[ \text{Mean} = \frac{11 + 7 + 12 + 8 + 9 + 5}{6} = \frac{52}{6} = 8.67 \]
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Variance:
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Calculate the squared differences from the mean:
- \( (11 - 8.67)^2 = (2.33)^2 = 5.4289 \)
- \( (7 - 8.67)^2 = (-1.67)^2 = 2.7889 \)
- \( (12 - 8.67)^2 = (3.33)^2 = 11.0889 \)
- \( (8 - 8.67)^2 = (-0.67)^2 = 0.4489 \)
- \( (9 - 8.67)^2 = (0.33)^2 = 0.1089 \)
- \( (5 - 8.67)^2 = (-3.67)^2 = 13.4689 \)
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Sum of squared differences: \[ 5.4289 + 2.7889 + 11.0889 + 0.4489 + 0.1089 + 13.4689 = 33.8334 \]
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Variance: \[ \text{Variance} = \frac{33.8334}{6} = 5.6389 \]
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Standard Deviation: \[ \text{Standard Deviation} = \sqrt{5.6389} \approx 2.38 \]
Dataset B: 10, 8, 10, 8, 8, 4
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Mean: \[ \text{Mean} = \frac{10 + 8 + 10 + 8 + 8 + 4}{6} = \frac{58}{6} = 9.67 \]
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Variance:
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Calculate the squared differences from the mean:
- \( (10 - 9.67)^2 = (0.33)^2 = 0.1089 \)
- \( (8 - 9.67)^2 = (-1.67)^2 = 2.7889 \)
- \( (10 - 9.67)^2 = (0.33)^2 = 0.1089 \)
- \( (8 - 9.67)^2 = (-1.67)^2 = 2.7889 \)
- \( (8 - 9.67)^2 = (-1.67)^2 = 2.7889 \)
- \( (4 - 9.67)^2 = (-5.67)^2 = 32.1489 \)
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Sum of squared differences: \[ 0.1089 + 2.7889 + 0.1089 + 2.7889 + 2.7889 + 32.1489 = 40.7334 \]
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Variance: \[ \text{Variance} = \frac{40.7334}{6} = 6.7889 \]
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Standard Deviation: \[ \text{Standard Deviation} = \sqrt{6.7889} \approx 2.60 \]
Results:
- The standard deviation of Dataset A is approximately 2.38.
- The standard deviation of Dataset B is approximately 2.60.
Therefore, the correct choice based on the calculated standard deviations should reflect that Dataset B has a larger standard deviation than Dataset A, indicating that Dataset B has more variability.
In the responses provided, none of the calculations match the results we derived here, which indicates that the values given in the original statement were likely miscalculated or incorrect.
So, to summarize:
- The standard deviation of Dataset A is approximately 2.38.
- The standard deviation of Dataset B is approximately 2.60.
- Dataset B has more variability than Dataset A.