At a large department store the average number of years of e

At a large department store, the average number of years of employment for a cashier is 6.0 with a standard deviation of 2.0 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 less than 8 years? Round your answer to 2 decimal places.

Solution

Normal Distribution
Mean ( u ) =6
Standard Deviation ( sd )=2
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
P(X < 9) = (9-6)/2
= 3/2= 1.5
= P ( Z <1.5) From Standard Normal Table
= 0.9332 ~ 93.32%