<PRE><B>Question 80942</B>
Let a random sample be taken of size n = 100 from a population with known standard deviation of o = 20 . Suppose that the mean of the sample is X = 37 . The approximate 68% confidence interval for the mean, u , of the population from which the sample was drawn is 
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E=z*sgma/sqrt(n)
E=0.994*20/sqrt(100)
E=0.994*2
E=1.988
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CI: (x-bar-E,x-bar+E)
CI: (37-1.988, 37+1.988)
CI: (35.012,38.988)
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Let me know if this is too difficult to follow and I will add 
some connecting comments.
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