Question 438811: 13 Chevrolet Corvettes were crash tested under a variety of conditions that simulate typical collisions. The mean repair cost for this sample of Corvettes was $16,540. The repair cost standard deviation for this sample was $6,782. Repair Costs for corvettes are believed to have a normal distribution. Construct a 99% confidence interval for the mean repair cost of all Corvettes involved in crashes.
mean= 16,540
St dev= 6,782
n=13
(2.578)(6,782/sq rt13)= 4849.188005
The answer is coming out wrong... can you tell me where i have gone wrong?
Thank you
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 13 Chevrolet Corvettes were crash tested under a variety of conditions that simulate typical collisions. The mean repair cost for this sample of Corvettes was $16,540. The repair cost standard deviation for this sample was $6,782. Repair Costs for corvettes are believed to have a normal distribution. Construct a 99% confidence interval for the mean repair cost of all Corvettes involved in crashes.
x-bar = 16,540
St dev= 6,782
n=13
ME = (2.576)(6,782/sq rt13)= 4845.11
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You're right.
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99% CI: 16,540-4845.11 < u < 16540+4845.11
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Cheers,
Stan H.
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