WEBVTT

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Here is the problem: Find the population standard deviation of 50, 55, 60, 65, 70, 75, 80.

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Treat the data as the entire population (divide by n).

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Find the mean.

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Square each deviation from the mean.

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Add the squared deviations.

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Divide by n to get the population variance.

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Take the square root.

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So the answer is σ equals 10.

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Standard deviation measures how spread out the values are around the mean. A small value means the data are clustered near the mean.

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Variance equals 100, and 10 squared equals 100.

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Sample SD for comparison: 10.8012345.