Question 930657
The Metropolitan Bus Company claims that the mean waiting time for a bus during rush hour is less than 5 minutes. A random sample of 20 waiting times has a mean of 3.2 minutes with a standard deviation of 2.1 minutes. At α = 0.01, test the bus company's claim. Assume the pupulation is normally distributed.
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Ho: u >= 5
Ha: u < 5 (claim)
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Critical value:: invNorm(0.01) = -2.3264
Test stat:: t(3.2) = (3.2-5)/(2.1/sqrt(20)) = -3.833
Since the test stat is in the reject interval, reject Ho.
there is sufficient evidence to support the claim
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Cheers,
Stan H.
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