SOLUTION: a manufacturer of light bulbs claims that its new light bulb has a mean life of 1,000 hours with a standard deviation of 80 hours. Assume the lifetimes of the bulbs are normally di

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Question 364268: a manufacturer of light bulbs claims that its new light bulb has a mean life of 1,000 hours with a standard deviation of 80 hours. Assume the lifetimes of the bulbs are normally distributed. What is the probability that a randomly chosen bulb will last more than 1,100 hours?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the z score,
z=%28x-mu%29%2Fsigma
z=%281100-1000%29%2F80
Once you have z, then find P(z).
P%28z%29=P%28x%3C=1100%29
.
.
P%28x%3C=1100%29%2BP%28x%3E1100%29=1
P%28x%3E1100%29=1-P%28x%3C=1100%29
P%28x%3E1100%29=1-P%28z%29