SOLUTION: A study of the amount of time it takes a mechanic to rebuild the transmission for a 2005 chevrolet cavalier shows that the mean is 8.4 hours and the standard deviation is 1.8 hours

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Question 1189038: A study of the amount of time it takes a mechanic to rebuild the transmission for a 2005 chevrolet cavalier shows that the mean is 8.4 hours and the standard deviation is 1.8 hours. if 40 mechanics are randomly selected, ?nd the probability that their mean rebuild time exceeds 8.7 hours
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
This is z>(8.7-8.4)/1.8/sqrt(40)
> 0.3*sqrt(40)/1.8
>1.054
that probability is 0.1459