Incorrect. In practice, we rarely know the value of σ (the population standard deviation) when we want to estimate the value of µ. So we use s (the sample standard deviation) to estimate σ.
Correct. In practice, we rarely know the value of σ (the population standard deviation) when we want to estimate the value of µ. So we use s (the sample standard deviation) to estimate σ.
Incorrect. Try again.
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