SOLUTION: assum that Z-scores are normally distrubuted with a mean of 0 and a standard deviation of 1.
Find p(Z more than or equal to 1.45)
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Find p(Z more than or equal to 1.45)
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Question 430247: assum that Z-scores are normally distrubuted with a mean of 0 and a standard deviation of 1.
Find p(Z more than or equal to 1.45) Found 2 solutions by ewatrrr, stanbon:Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website! If IQ scores are normally distributed with a mean of 100 and a standard deviation of 15.
- Find the probability that the mean IQ score is between 90 and 95, if 9 IQ scores are randomly selected.
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t(90) = (90-100)/[15/sqrt(100)] = -10/[1.5] = -6.6667
t(95) = (95-100)/[15/sqrt(100)] = -5/[1.5] = -3.3333
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P(90< x-bar <95) = P(-6.6667< t < -3.3333 when df=8) = 0.0051
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Cheers,
Stan H.
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