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: D. 3
- Step 1: The standard deviation of the sample mean is . Step 2. . Answer: 3. Why not the others: : That divides by rather than . 15: 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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