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. 
x-bar =  16,540
St dev= 6,782
n=13 
ME = (2.576)(6,782/sq rt13)= 4845.11
------------------
You're right.
----
99% CI: 16,540-4845.11 < u < 16540+4845.11
====================
Cheers,
Stan H.