SOLUTION: the lifetime of a battery is normally distributed with a mean life of 40 hours and a standard deviation of 1.2 hours. find the probability that a randomly selected battery lasts lo

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Question 609928: the lifetime of a battery is normally distributed with a mean life of 40 hours and a standard deviation of 1.2 hours. find the probability that a randomly selected battery lasts longer than 42 hours?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

40 hours and a standard deviation of 1.2 hours

P(lasts longer than 42 hours) = 1 -P(z ≤ (42-40)/1.2) = 1 -NORMSDIST(1.6667)= .0478