The weights of items have standard deviation g. What is the standard deviation of the mean weight of a random sample of items?

Answer and explanation

Correct answer: B. 3

  1. Step 1: The standard deviation of the sample mean is . Step 2. . Answer: 3. Why not the others: : That divides by rather than . 6: That is the standard deviation of a single item. 9: That is the variance of the mean, not its standard deviation.

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The weights of items have standard… | Singapore GCE A-Level