SOLUTION: Suppose the mean heights all sixth-grade students follow normal distraction with mean 50 inches and 3 inches? Suppose you take a sample of 250 students. Give the shape, center an

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Question 1115191: Suppose the mean heights all sixth-grade students follow normal distraction with mean 50 inches and 3 inches?
Suppose you take a sample of 250 students. Give the shape, center and standard-deviation of the sampling distribution of samples means. Find the probability that a sample mean is below 52.5 inches?
Answer by stanbon(75887) (Show Source):
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Suppose the mean heights all sixth-grade students follow normal distraction with mean 50 inches and standard distribution = 3 inches?
Suppose you take a sample of 25 students.
Give the shape:: normal distribution
center:: mean of the sample means = mean of the population = 50
standard-deviation of the sample means = 3/sqrt(25)
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Find the probability that a sample mean is below 52.5 inches?
z(52.5) = (52.5-50)/(3/sqrt(25)) = 2.5*sqrt(25)/3 = 4.167
P(x-bar < 52.5) = P(z < 4.167) = normalcdf(-100,4.167) = 0.99998
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Cheers,
Stan H.
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