Question 240666
Football fans claim that it takes 35 minutes to get out of the stadium after a game when over 30000 fans attend the game.
To determine if the complains are justified , a random sample of 100 fans is taken. The average time it takes these 100 fans to exit the parking is 27 minutes and sample standard deviatian is 7 minutes. 
a) Estimate the mean departe time = 27 minutes?
b) Construct a 95% CI for the mean departure time and interpret the result?
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sample mean: 27 min
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standard error: SE = t*s/sqrt(n)
t = invT(0.025,99) = 1.9842
SE = 1.9842*7/sqrt(100) = 1.389
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95% CI: 27-1.389 < u < 27+1.389
95% CI: 25.61 < u < 28.389
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Meaning: We are 95% confident the mean departure time is between
25.61 min and 28.389 min
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Cheers,
Stan H.