The average hourly wage of workers at a fast food restaurant

The average hourly wage of workers at a fast food restaurant is $6.50/hr. Assume the wages are normally distributed with a standard deviation of $0.45. If a worker at this fast food restaurant is selected at random, what is the probability that the worker earns more than $7.35? Round your answer to two decimal places.

Solution

Normal Distribution
Mean ( u ) =6.5
Standard Deviation ( sd )=0.45
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
P(X > 7.35) = (7.35-6.5)/0.45
= 0.85/0.45 = 1.8889
= P ( Z >1.889) From Standard Normal Table
= 0.0295 ~ 0.03