Question 955025: If X has a normal distribution with mean 80 and standard deviation 12, what is the distribution of the mean of a sample of 9 of these values? Give the values of the parameters.
Please help me with this -
If X has a normal distribution with mean 80 and standard deviation 12, what is the distribution of the mean of a sample of 9 of these values? Give the values of the parameters.
Please help me with this, I'm so confused. Thank you.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! If X has a normal distribution with mean 80 and standard deviation 12, what is the distribution of the mean of a sample of 9 of these values? Give the values of the parameters.
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The Central Limit Theorem says:
1. The mean of the sample means = the mean of the population.
So your x-bar = u = 80
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2. The std of the sample means = (std of population)/sqrt(sample size)
So your sample std = 12/sqrt(9) = 12/3 = 4
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Cheers,
Stan H.
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