# Thread: The Normal Distribution (Elementary Statistic)

1. ## The Normal Distribution (Elementary Statistic)

How do I solve this question?

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?

2. ## Re: The Normal Distribution (Elementary Statistic)

Let X be the number of years that a randomly selected cashier has worked.

$P(X > 10) = 1 - P(X \leq 10) = Q\left(\frac{10-5.7}{1.8} \right)$