SOLUTION: A general electric soft white three-way light bulb has an average life of 1200 hours, with a standard deviation of 50 hours. Find the probability that the life of one of these bu

Algebra ->  Probability-and-statistics -> SOLUTION: A general electric soft white three-way light bulb has an average life of 1200 hours, with a standard deviation of 50 hours. Find the probability that the life of one of these bu      Log On


   

Question 975383: A general electric soft white three-way light bulb has an average life of 1200 hours, with a standard deviation of 50 hours.
Find the probability that the life of one of these bulbs will be between 1150 and 1300 hours.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the z scores, then the probability.
z%5B1%5D=%281150-1200%29%2F50=-50%2F50=-1
z%5B2%5D=%281300-1200%29%2F50=100%2F50=2
So then use a normal distribution table to find,
P=P%28z%5B2%5D%29-P%28z%5B1%5D%29