Question 756402
The length of country and western songs is normally distributed and has a mean of 200 seconds and a standard deviation of 30 seconds. Find the probability that a random selection of 9 songs will have mean length of 186.30 seconds or less. Assume the distribution of the lengths of the songs is normal
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t(186.3) = (186.3-200)/[30/sqrt(9)] = -1.3700
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P(x < 186.3) = P(t < -1.3700,when df = 8) = tcdf(-100,-1.37,8) = 0.1039
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Cheers,
Stan H.
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