SOLUTION: The annual precipitation amounts in a certain mountain range are normally distributed with a mean of 85 inches, and a standard deviation of 14 inches. What is the probability that

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Question 1102343: The annual precipitation amounts in a certain mountain range are normally distributed with a mean of 85 inches, and a standard deviation of 14 inches. What is the probability that the mean annual precipitation during 49 randomly picked years will be less than 87.8 inches?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
use a z-test
z<=(xbar-x)/(sigma/sqrt(n))
z<=(87.8-85)/(14/7), since sqrt (49)=7
z<=2.8/2<=+1.4
That probability is 0.9192.