Standard Deviation Statistics Example 4

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Example 4

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Calculate the population standard deviation of the data set: 3, 3, 7, 7.

Solution

  1. 1
    Step 1: The mean is 3+3+7+74=5\frac{3+3+7+7}{4} = 5. The squared deviations are 4, 4, 4, and 4.
  2. 2
    Step 2: The population variance is 164=4\frac{16}{4} = 4, so the population standard deviation is 4=2\sqrt{4} = 2.

Answer

ฯƒ=2\sigma = 2
Standard deviation measures typical distance from the mean. When the deviations are symmetric and easy to square, the calculation clearly shows how variance and standard deviation are related.

About Standard Deviation

Standard deviation is a measure of how spread out data values are from the mean, representing the typical distance of data points from the average. A small standard deviation means data clusters tightly around the mean; a large one means data is widely spread.

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