Question 379954: At a large department store, the average number of years of employment for a cashier is 5.7 with a standard deviation of 1.8 years. If the number of years of employment at this department store is normally distributed, what is the probability that a cashier selected at random has worked at the store for over 10 years?
A)0.4916
B)0.9916
C)0.0084
D)0.0054
I have tried, but think I am using the wrong formula? I tried z=(x-mu)/o (<--standard deviation)
z=10-5.7/1.8 = 2.38
Using Table E I get 0.4913. I then subtract from 0.5000 since we are looking for MORE than 10 years and I get 0.0087. However, this isn't a choice listed above. So I know I am missing something somewhere. Help would be appreciated. Thanks!
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! You should have gotten P(Z < 2.38) = 0.9916, then you subtract that answer from 1 to get 1 - 0.9916 = 0.0084
So the answer is C)
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