A standard fluorescent tube has life length that is basically distributed with mean of 6900 hours and standard deviation of 1000 hours. A competitor has developed the compact fluorescent lighting system which will fit into incandescent sockets. It claims the new compact tube has a normally distributed life length with mean of 7320 hours and standard deviation of 1200 hours.
A) Determine the probability that each tube will have a life greater than 9,000 hours?
Standard fluorescent tube:
Competitor's new compact tube:
B) Which fluorescent tube is more likely to have life length greater than 9,000 hours?