SOLUTION: 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, and the distribution is approximately normal. If

Algebra ->  Probability-and-statistics -> SOLUTION: 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, and the distribution is approximately normal. If      Log On


   



Question 1085499: 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, and the distribution is approximately normal. If an employee is picked at random, what is the probability that the employee has worked at the store for over 10 years?
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
Probability (P) ( X > 10 ) = 1 - P ( X < or = 10 )
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we calculate the z-score
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z-score = ( 10 - 5.7 ) / 1.8 = 2.3889
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look in z-tables for the associated P
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P ( X < or = 10) = 0.9981
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P ( X > 10 ) = 1 - 0.9981 = 0.0019
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